Refrigerator having very low temperature freezer compartment

ABSTRACT

A refrigerator that includes: a storage space configured to be cooled by a refrigeration cycle cooling system; a wall defines a boundary of the storage space; a low temperature case that is arranged adjacent to a portion of a first surface of the wall; a thermoelectric element module (TEM) assembly that is configured to supply cool air to the low temperature case; and a TEM accommodating part that protrudes from the first surface of the wall and that accommodates the TEM assembly, wherein the low temperature case includes an opening through which the TEM accommodating part is inserted, and wherein a sealant is provided between the low temperature case and the wall to couple the low temperature case to the first surface of the wall is disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2017-0001595, filed on Jan. 4, 2017, the disclosureof which is incorporated herein by reference in its entirety.

BACKGROUND 1. Field of the Invention

The present invention relates to a refrigerator having a very lowtemperature freezer compartment, and more particularly, to arefrigerator for reliably preventing leakage of cool air in a very lowtemperature freezing space to the outside and allowing a very lowtemperature freezer compartment and a thermoelectric element module(TEM) assembly to be easily installed.

2. Discussion of Related Art

Generally, a refrigerator is a home appliance that stores food at a lowtemperature, and can be divided into a refrigerator compartment and afreezer compartment according to a temperature of food stored in therefrigerator. Generally, a refrigerator compartment maintains atemperature of 3 to 4° C., and a freezer compartment maintains atemperature of about −20° C.

The freezer compartment having a temperature of about −20° C. is a spacein which food is kept frozen and is mainly used by consumers to storefood for long periods of time. However, an existing freezer compartmentwhich maintains a temperature of about −20° C. has a problem in that, ina case in which meat or seafood are frozen, when moisture in cells ofthe meat or seafood is frozen, a phenomenon in which the moisture isdrained outside the cells and the cells are destroyed occurs, and as aresult, when the meat or seafood are cooked after being defrosted, anoriginal taste thereof is lost or a texture is changed.

On the other hand, in the case of meat or seafood being frozen, when thefreezing is performed while a temperature rapidly passes through afreezing point temperature zone in which intracellular ice is formed,destruction of the cells can be minimized. Therefore, even after themeat or seafood is defrosted, fleshiness and texture of the food can beproperly renewed or reproduced, and thus delicious dishes can be made.

Because of this, high-class restaurants use very low temperaturefreezers that can rapidly freeze meat, fish, seafood, and the like.However, since it is not always necessary to use a very low temperaturefreezer in an ordinary home unlike a restaurant that needs to preservelarge quantities of food, it is not easy to separately purchase and usea very low temperature freezer that is used in a restaurant.

However, as quality of life has improved, a customer's desire to eatmore delicious food has increased, and accordingly, customers who wantto use a very low temperature freezer have increased.

In order to meet the needs of such customers, household refrigerators inwhich a very low temperature freezer compartment is installed in aportion of a freezer compartment are being developed. The very lowtemperature freezer compartment preferably satisfies a temperature ofabout −50° C., and such an extremely low temperature is a temperaturethat cannot be attained by only a refrigeration cycle using aconventional refrigerant.

Accordingly, household refrigerators in which a very low temperaturefreezer compartment is separately provided in a freezer compartment arebeing developed through a method in which cooling is performed up to atemperature of about −20° C. using a refrigeration cycle and thencooling is performed at a very low temperature lower than −20° C. usinga TEM.

However, since a temperature difference between a freezer compartment at−20° C. and a very low temperature freezer compartment at −50° C. issignificantly large, it is not easy to implement the temperature of −50°C. only by directly applying a structure in which heat insulating,defrosting, and cold air supplying are performed, which has been appliedto an existing freezer compartment design, to the very low temperaturefreezer compartment.

Therefore, in order to smoothly implement an extremely low temperatureof the very low temperature freezer compartment, it is necessary toblock introduction of air in the freezer compartment at a temperature of−20° C., which is higher than −50° C., into a very low temperaturefreezing space which maintains a temperature of −50° C. inside the verylow temperature freezer compartment.

A very low temperature case forming the very low temperature freezercompartment should be manufactured and assembled separately from a grillfan assembly, and a very low temperature compartment door that can openand close the very low temperature case should be installed on a frontside of the very low temperature case. Therefore, an assembled structureof the very low temperature case and the grill fan assembly should havea structure in which the very low temperature case is firmly fixed tothe grill fan assembly and introduction of air in the freezercompartment into an inner space of the very low temperature case throughsuch fixed portions is prevented, and is required to have a structure inwhich the air in the freezer compartment is also prevented from beingintroduced into the inner space of the very low temperature case eventhrough a gap between the very low temperature case and the very lowtemperature compartment door.

Since an assembly including a thermoelectric element installed forcooling the very low temperature freezing space of the very lowtemperature freezer compartment is installed in the grill fan assembly,when a gap existing at a fastening portion of the assembly of thethermoelectric element and the grill fan assembly is a portion at whichthe very low temperature freezing space is in conjunction with a generalfreezing space, a structure for preventing introduction of air in thefreezer compartment into an inner space of the very low temperaturecase, that is, a sealing structure, is required therebetween.

In addition, even when a gap between the grill fan and a shroud of thegrill fan assembly in which the assembly of the thermoelectric elementis installed is the portion at which the very low temperature freezingspace is in conjunction with the general freezing space, the structurefor preventing the introduction of the air in the freezer compartmentinto the inner space of the very low temperature case, that is, thesealing structure, is required therebetween.

SUMMARY

The present invention is directed to a refrigerator structure in whichan extremely low temperature is smoothly implemented and maintained byall gaps around a very low temperature freezing space through which itis possible for a very low temperature freezing space to be inconjunction with a freezing space of a general freezer compartment beingthoroughly sealed.

The present invention is directed to a refrigerator having a structurein which a TEM assembly is easily assembled and also reliably sealed.

The present invention is directed to a refrigerator further including acompression structure in which sealing can be reliably performed evenbetween a very low temperature case which is opened and closed and avery low temperature compartment door.

In general, one innovative aspect of the subject matter described inthis specification can be implemented in a refrigerator comprising: astorage space configured to be cooled by a refrigeration cycle coolingsystem; a wall that is located at a first side of the storage space andthat is configured to define a boundary of the storage space at a firstside of the storage space; a low temperature case that is located in thestorage space and that is arranged adjacent to a portion of a firstsurface of the wall, the first surface facing the storage space; a TEMassembly that is located at a first side of the low temperature case,that is coupled to a portion of a second surface of the wall, theportion of the second surface corresponding to the portion of the firstsurface of the wall, and that is configured to supply cool air to thelow temperature case; and a TEM accommodating part that protrudes fromthe first surface of the wall and that accommodates the TEM assembly,wherein the low temperature case includes an opening through which theTEM accommodating part is inserted, and wherein a sealant is providedbetween the low temperature case and the wall to couple the lowtemperature case to the first surface of the wall.

The foregoing and other implementations can each optionally include oneor more of the following features, alone or in combination. Inparticular, one implementation includes all the following features incombination. An inner circumferential surface of the opening of the lowtemperature case surrounds an outer circumferential surface of the TEMaccommodating part, and wherein a sealant is applied between the innercircumferential surface of the opening of the low temperature case andthe outer circumferential surface of the TEM accommodating part tocouple the inner circumferential surface of the opening of the lowtemperature case to the outer circumferential surface of the TEMaccommodating part. A peripheral surface of the opening contacts aperipheral surface of the TEM accommodating part, and wherein a sealantis applied between the peripheral surface of the opening and theperipheral surface of the TEM accommodating part to couple theperipheral surface of the opening to the peripheral surface of the TEMaccommodating part. The inner circumferential surface of the openingincludes a surface inclined outwardly toward the wall, wherein the outercircumferential surface of the TEM accommodating part includes a surfaceinclined outwardly toward the wall, and wherein the surface of the innercircumferential surface is inclined at the same angle as the surface ofthe outer circumferential surface. A portion of the innercircumferential surface overlaps with the outer circumferential surface,and wherein a length of the portion of the inner circumferential surfaceis between 30 and 40 mm. The refrigerator further comprises: a lowtemperature compartment door that is configured to open or close anopening of the low temperature case, the opening being located at asecond side of the storage space; and a gasket that is configured toshield a gap between the low temperature compartment door and the lowtemperature case. The refrigerator further includes: a compressionstructure that is configured to compress the gasket using a forceapplied to close the low temperature compartment door. The compressionstructure includes: a first magnetic unit that is coupled to the lowtemperature compartment door, and a second magnetic unit that is coupledto the low temperature case, and wherein the first magnetic unit and thesecond magnetic unit mutually attract each other. The compressionstructure includes: a protrusion that is coupled to the low temperaturecompartment door, and a locking groove that is coupled to the lowtemperature case and that is configured to be engaged with theprotrusion. The refrigerator further includes: a low temperature traythat is coupled to the low temperature compartment door and that ismovable between a first position and a second position, wherein, (i) ina state in which the low temperature tray is located at the firstposition, at least one portion of the low temperature tray is outside ofthe low temperature case, and (ii) in a state in which the lowtemperature tray is located at the second position, the low temperaturetray is inside the low temperature case; an outer rail guide that iscoupled to the low temperature tray through the low temperaturecompartment door and that is configured to be moved with the lowtemperature tray; and an outer rail that is coupled to the lowtemperature case and that is configured to guide the outer rail guide inmoving the low temperature tray between the first position and thesecond position, wherein the compression structure includes a dampingclosure that is coupled to the outer rail or the outer rail guide andthat is configured to move the outer rail guide at a first speed. Thecompression structure includes: a structure that is configured to pressthe low temperature compartment door in a state in which a refrigeratordoor of the refrigerator is closed.

In general, another innovative aspect of the subject matter described inthis specification can be implemented in a water purifier comprising: afreezer compartment; a grill fan that is located at a first side of thefreezer compartment; a low temperature case that is located at aninterior area of the freezer compartment and that is arranged adjacentto a portion of a first surface of the grill fan; a TEM assembly that islocated at a first side of the low temperature case, that is coupled toa first portion of a second surface of the grill fan, the first portionof the second surface corresponding to a portion the first surface ofthe grill fan, and that is configured to supply cool air to the lowtemperature case; a TEM accommodating part that is coupled to the grillfan and that accommodates the TEM assembly; and a shroud that is coupledto the grill fan, that is configured to distribute cool air supplied tothe freezer compartment, and that includes (i) an abutting surface beingcoupled to a second portion of the second surface of the grill fan, thesecond portion of the second surface corresponding to the TEMaccommodating part and (ii) a TEM insertion hole that is connected to aninterior area of the TEM accommodating part, wherein a sealant isapplied between the second surface of the grill fan and the abuttingsurface of the shroud to couple the shroud to the grill fan.

The foregoing and other implementations can each optionally include oneor more of the following features, alone or in combination. Inparticular, one implementation includes all the following features incombination. The TEM assembly includes: a cold sink, a thermoelectricelement, a heat insulating material, a heat sink, a module housing thatis configured to accommodate and fix at least one of the cold sink, thethermoelectric element, the heat insulating material, and the heat sink,and a flange that is coupled to the module housing, that extendsoutwardly, and that is fixed to the grill fan by coupling to theabutting surface of the shroud, and wherein the cold sink, thethermoelectric element, and the heat sink are orderly arranged in adirection from a second side of the module housing to the first side ofthe module housing. A sealant is applied between the flange and theabutting surface to couple the TEM assembly to the grill fan. A portionof the flange is overlapped with the abutting surface, and wherein alength of the portion of the flange is between 5 and 15 mm. The TEMassembly includes: a cold sink, a thermoelectric element, a heatinsulating material, a heat sink, a module housing that is configured toaccommodate and fix at least one of the cold sink, the thermoelectricelement, the heat insulating material, and the heat sink, a flange thatis coupled to the module housing, that extends outwardly, and that isfixed to the grill fan by coupling to the abutting surface of theshroud, and a spacer that is coupled to the flange, that protrudes fromthe flange, that is supported by an inner case of the refrigerator, andthat is configured to make a space between the grill fan and the innercase of the refrigerator, and wherein the cold sink, the thermoelectricelement, and the heat sink are orderly arranged in a direction from asecond side of the module housing to the first side of the modulehousing. The TEM assembly includes: a cold sink, a thermoelectricelement, a heat insulating material, a heat sink, and a module housingthat is configured to accommodate and fix at least one of the cold sink,the thermoelectric element, the heat insulating material, and the heatsink, wherein the cold sink, the thermoelectric element, and the heatsink are orderly arranged in a direction from a second side of themodule housing to the first side of the module housing, and wherein thecold sink is located at a first side of the grill fan and thethermoelectric element and the heat sink are located at a second side ofthe grill fan. A first end of the cold sink is located adjacent to thegrill fan.

In general, another innovative aspect of the subject matter described inthis specification can be implemented in a water purifier comprising: afreezer compartment; a grill fan that is located at a first side of thefreezer compartment; a low temperature case that is located at aninterior area of the freezer compartment and that is arranged adjacentto a portion of a first surface of the grill fan; a TEM assembly that islocated at a first side of the low temperature case, that is coupled toa first portion of a second surface of the grill fan, the first portionof the second surface corresponding to a portion the first surface ofthe grill fan, and that is configured to supply cool air to the lowtemperature case; a TEM accommodating part that is coupled to the grillfan and that accommodates the TEM assembly; a shroud that is coupled tothe grill fan and that is configured to distribute cool air supplied tothe freezer compartment; a rear rib that is coupled to the first surfaceof the grill fan and that extends outwardly from an outer periphery ofthe TEM accommodating part; and a rib abutting surface that is coupledto the shroud and that extends outwardly to be in contact with an innersurface of the rear rib, wherein a sealant is applied between the secondsurface of the grill fan and the rib abutting surface of the shroud tocouple the shroud to the grill fan.

The foregoing and other implementations can each optionally include oneor more of the following features, alone or in combination. Inparticular, one implementation includes all the following features incombination. The TEM assembly includes: a cold sink, a thermoelectricelement, a heat insulating material, a heat sink, and a module housingthat is configured to accommodate and fix at least one of the cold sink,the thermoelectric element, the heat insulating material, and the heatsink, wherein a portion of an outer edge of a flange that facesoutwardly from the module housing of the TEM assembly is controlled byan inner surface of the rib abutting surface of the shroud such that themodule housing is located relative to an abutting surface of the shroud,and wherein the cold sink, the thermoelectric element, and the heat sinkare orderly arranged in a direction from a second side of the modulehousing to the first side of the module housing.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will become more apparent to those of ordinary skill in theart by describing exemplary embodiments thereof in detail with referenceto the accompanying drawings, in which:

FIG. 1 is a perspective view illustrating a refrigerator according tothe present invention in a state in which doors thereof are opened;

FIGS. 2A to 2C are perspective views illustrating a state in which agrill fan assembly and a very low temperature freezer compartment areinstalled in an inner case of a freezer compartment of a refrigeratormain body of the present invention, a partition wall, and a side wall ofthe inner case, respectively;

FIG. 3 is a front perspective view illustrating a state in which thegrill fan assembly, the very low temperature freezer compartment, and aTEM assembly of the freezer compartment according to the presentinvention are disassembled;

FIG. 4 is a perspective view illustrating a shroud of the grill fanassembly;

FIG. 5 is an enlarged perspective view of a TEM accommodating part;

FIG. 6 is a rear perspective view of FIG. 3;

FIG. 7 is a cross-sectional view taken along line A-A of FIG. 2A;

FIG. 8 is a cross-sectional view (from which a heating wire is omitted)taken along line B-B′ of FIG. 3;

FIG. 9 is a perspective view of a side section of the grill fan assemblyin which the TEM assembly is installed when viewed from the rear;

FIG. 10 is a cross-sectional view taken along line Z-Z of FIG. 9;

FIG. 11 is a cross-sectional view taken along line X-X of FIG. 9;

FIG. 12 is a cross-sectional view taken along line C-C of FIG. 7;

FIG. 13 is an exploded perspective view of the TEM assembly according tothe present invention;

FIG. 14 is a front perspective view illustrating a modified example ofthe TEM assembly according to the present invention;

FIG. 15 is a rear perspective view of the modified example of FIG. 14;

FIGS. 16A and 16B are cross-sectional views taken along line I-I of FIG.6;

FIGS. 17A and 17B are enlarged perspective views of a portion J of FIG.8 when viewed from the rear;

FIG. 18 is a view illustrating a refrigeration cycle applied to therefrigerator according to the present invention;

FIG. 19 is a view illustrating another embodiment of the refrigerationcycle applied to the refrigerator according to the present invention;

FIG. 20 is an enlarged perspective view illustrating a state in which arefrigerant pipe behind a capillary tube of a refrigeration cycle and acapillary tube in front of an evaporator are connected to a refrigerantinlet pipe (151) and a refrigerant outlet pipe (152) of a TEM assemblyfixed to a grill fan assembly, respectively;

FIG. 21 is a side cross-sectional view illustrating an example in whichthe very low temperature freezer compartment of the present invention isinstalled in a refrigerator compartment;

FIG. 22 is an enlarged cross-sectional view taken along line I-I of FIG.6;

FIG. 23 is an enlarged perspective view of the portion J of FIG. 8 whenviewed from the rear;

FIG. 24 is a side cross-sectional view illustrating a state in which avery low temperature compartment door and a very low temperature trayare withdrawn from the very low temperature case assembled in the grillfan assembly;

FIG. 25 is an enlarged side cross-sectional view illustrating a state inwhich the very low temperature compartment door in the very lowtemperature case of FIG. 24 is closed; and

FIG. 26 illustrates cross-sectional views taken along lines Q-Q and R-Rof FIG. 24.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings.

The present invention is not limited to the embodiments that will bedisclosed, and may be implemented in various different forms. Theembodiments are provided in order to fully explain the present inventionand the scope of the present invention to those skilled in the art.

In the present invention, the term “very low temperature” refers to atemperature lower than −20° C., which is a typical freezing storagetemperature of a freezer compartment, and a range thereof is notnumerically limited thereto. Also, even in the very low temperaturefreezer compartment, a storage temperature thereof includes −20° C. andmay be higher than −20° C.

[Overall Structure of Refrigerator Having Very Low Temperature FreezerCompartment]

FIG. 1 is a perspective view illustrating a refrigerator according tothe present invention in a state in which doors thereof are opened, andFIGS. 2A to 2C are perspective views illustrating a state in which agrill fan assembly and a very low temperature freezer compartment areinstalled in an inner case of a freezer compartment of a refrigeratormain body of the present invention, a partition wall, and a side wall ofthe inner case, respectively.

The refrigerator according to the present invention includes arefrigerator main body 10 having a rectangular parallelepiped shape anda refrigerator door 20 opening and closing each of spaces of a cabinetin front of the main body. The refrigerator of the present invention hasa bottom freezer structure in which a refrigerator compartment 30 isprovided at an upper portion thereof and a freezer compartment 40 isprovided at a lower portion thereof, and the refrigerator compartmentand the freezer compartment have side-by-side type doors 21 and 22,respectively, which are rotated and opened relative to hinges 25 at bothends of the refrigerator compartment 30 and the freezer compartment 40.However, the present invention is not limited to the refrigerator havingthe bottom freezer structure, and any refrigerator having a structure inwhich a very low temperature freezer compartment is installed in afreezer compartment may also be applied as a refrigerator having aside-by-side structure in which a refrigerator compartment and a freezercompartment are disposed on left and right sides, respectively, arefrigerator having a top mount structure in which a freezer compartmentis disposed above a refrigerator compartment, and the like.

The refrigerator main body 10 includes an outer case 11 which forms anexterior of the refrigerator and an inner case 12 which is spaced apredetermined distance from the outer case 11 and constitutes aninterior of each of the refrigerator compartment 30 and the freezercompartment 40. A heat insulating material 80 is foamed in a spacebetween the outer case 11 and the inner case 12, which is filled withthe heat insulating material 80, so that the refrigerator compartment 30and the freezer compartment 40 are heat-insulated from an indoor space.

A shelf 13 and a drawer 14 are installed in storage spaces of therefrigerator compartment 30 and the freezer compartment 40 to increasespace-using efficiency and store food, and may be guided along rails 15disposed on left and right sides of the storage spaces and installedtherein. As illustrated in the drawings, door baskets 27 are installedinside the refrigerator compartment door 21 and the freezer compartmentdoor 22 are suitable for storing containers of drinks and the like.

A very low temperature freezer compartment 200 according to the presentinvention is provided in the freezer compartment 40. A space of thefreezer compartment 40 is partitioned by a partition wall 42 extendingvertically at a center of the freezer compartment to be divided intoleft and right sides for efficient use of space. Referring to FIGS. 2Ato 2C, the partition wall 42 is installed to be fitted in an inwarddirection from a front side of the cabinet, and may be supported in thefreezer compartment by a mounting guide 42-1 provided at a bottom of therefrigerator. According to the present invention, the very lowtemperature freezer compartment 200 is illustrated as being located onan upper right side of the freezer compartment 40. However, the presentinvention is not necessarily limited to the very low temperature freezercompartment 200 being provided in the freezer compartment. That is, thevery low temperature freezer compartment 200 of the present inventionmay be provided in the refrigerator compartment 30. However, since atemperature difference between an inside and outside (a freezercompartment atmosphere) of the very low temperature freezer compartmentwhen the very low temperature freezer compartment 200 is installed inthe freezer compartment 40 is smaller when being installed in therefrigerator compartment 30, it is more advantageous for the very lowtemperature freezer compartment 200 to be installed in the freezercompartment from the viewpoint of cool air leakage prevention and heatinsulation.

A machine compartment isolated from the freezer compartment is locatedat a lower rear portion of the freezer compartment, and a compressor 71and a condenser 73 of a refrigeration cycle cooling system 70 using arefrigerant are disposed in the machine compartment. A grill fanassembly 50, which includes a grill fan 51 configured to define a rearwall of the freezer compartment and a shroud 56 which is coupled to arear of the grill fan 51 to distribute cool air in the freezercompartment, is installed in a space formed between the freezercompartment and a rear wall of the inner case 12. An evaporator 77 ofthe refrigeration cycle cooling system 70 is installed in a space with apredetermined size between the grill fan assembly 50 and the rear wallof the inner case 12. The refrigerant evaporated when a refrigerantinside the evaporator 77 is evaporated exchanges heat with air flowingin an inner space of the freezer compartment, and the air cooled by theheat exchange is distributed in a cool air distribution space defined bythe grill fan 51 and the shroud 56 and flows into the freezercompartment to cool the freezer compartment.

[Cooling Structure of Very Low Temperature Freezer Compartment andFreezer Compartment Including Very Low Temperature Freezer Compartment]

FIG. 3 is a front perspective view illustrating a state in which thegrill fan assembly, the very low temperature freezer compartment, and aTEM assembly of the freezer compartment according to the presentinvention are disassembled, FIG. 4 is a perspective view illustrating ashroud of the grill fan assembly, FIG. 5 is an enlarged perspective viewof a TEM accommodating part, FIG. 6 is a rear perspective view of FIG.3, FIG. 7 is a cross-sectional view taken along line A-A of FIG. 2A,FIG. 8 is a cross-sectional view taken along line B-B′ of FIG. 3, FIG. 9is a perspective view of a side section of the grill fan assembly inwhich the TEM assembly is installed when viewed from the rear, FIG. 10is a cross-sectional view taken along line Z-Z of FIG. 9, FIG. 11 is across-sectional view taken along line X-X of FIG. 9, and FIG. 12 is across-sectional view taken along line C-C of FIG. 7.

First, referring to FIGS. 3, 4, and 6, as an embodiment according to thepresent invention, the grill fan assembly 50 to which the very lowtemperature freezer compartment 200 is applied includes the grill fan 51configured to define the rear wall of the freezer compartment and theshroud 56 configured to distribute cool air cooled by exchanging heatwith the above-described evaporator 77 on a rear surface of the grillfan 51 and supply the cool air to the freezer compartment.

Cool air outlet pipes 52 which serve as paths for discharging cool airin a forward direction are provided as illustrated in the grill fan 51.In the illustrated embodiment, the cool air outlet pipes 52 are providedat upper left and right sides 52-1 and 52-2, central left and rightsides 52-3 and 52-4, and lower left and right sides 52-5 and 52-6 (inFIG. 3, the cool air outlet pipes at the central left side and the lowerleft side are covered by the very low temperature freezer compartment).

The shroud 56 is coupled to the rear of the grill fan 51 and defines aspace with a predetermined size with the rear surface of the grill fan51 after being coupled thereto. The space serves as a space fordistributing the air cooled by the evaporator 77 provided on the rearsurface of the shroud 56 or the grill fan assembly 50. A cool air intakehole 58 configured to be in conjunction a space behind the shroud 56with the space between the grill fan 51 and the shroud 56 is provided ata substantially central upper portion of the shroud 56. Further, a fan57 configured to suction cool air in the space behind the shroud 56through the cool air intake hole 58 and pressurize and distribute thecool air in the space between the grill fan 51 and the shroud 56 isinstalled inside the cool air intake hole 58 in the space between thegrill fan 51 and the shroud 56.

The cool air pressurized by the fan 57 flows into the space between thegrill fan 51 and the shroud 56, is appropriately distributed, and isdischarged in the forward direction through the cool air outlet pipes52, which are open in a forward direction of the grill fan 51. Referringto FIG. 4, a fan (see FIG. 6) provided in front of the cool air intakehole 58 is, for example, a sirocco fan that rotates in acounterclockwise direction, sucks cold air in the freezer compartmentthrough the cool air intake hole 58, and then discharges the cold air ina radial direction. The cool air is guided by guide partitions 591, 592,593, and 594 which reduce a flow loss of the cool air and guide aflowing direction of the air so that the air is distributed and flowsinto the cool air outlet pipes 52 located at both of the upper sides52-1 and 52-2, both of the central sides 52-3 and 52-4, and both of thelower sides 52-5 and 52-6 of the grill fan. A protrusion provided abovethe cool air outlet pipe 52-3 of the grill fan 51 in FIG. 12 is awaterway groove 512 protruding in the forward direction in a slim form,and has a structure in which dew condensation that can be formed on aninner wall of the grill fan 51 is prevented from flowing through thecool air outlet pipes 52-3 and 52-5 while flowing downward. That is, thewaterway groove 512 of the grill fan 51 has a concave groove shape on aback surface of the grill fan and has a shape inclined downward from aleft to a center so that water droplets flowing downward from above mayfall down. As a result, the water droplets do not move into the cold airoutlet pipe.

Air discharged into the freezer compartment 40 through the cool airoutlet pipes 52 spreads uniformly inside the freezer compartment andflows to the door basket 27 of the freezer compartment door 22.Therefore, the air cooled by the evaporator 77 is uniformly suppliedinto the freezer compartment to cool the freezer compartment.

Meanwhile, referring to FIGS. 3 and 5 to 12, A TEM accommodating part 53in which a TEM assembly 100 configured to freeze the very lowtemperature freezer compartment 200 at a very low temperature isprovided between the upper right side cool air outlet pipe 52-2 and thecentral right side cool air outlet pipe 52-4 at an upper right portionof the grill fan 51.

First, referring to FIGS. 3 and 5, the TEM accommodating part 53 isprovided on a front surface of the grill fan 51 to correspond to aposition of the freezer compartment 40 at which the very low temperaturefreezer compartment 200 is installed. The TEM accommodating part 53 maybe integrally molded with a wall defining a rear boundary of the freezercompartment 40, which is one of storage spaces in which cooling isperformed by the refrigeration cycle cooling system 70, that is, withthe grill fan 51, or may be installed via a manner in which the TEMaccommodating part 53 is manufactured and assembled as a separate partfrom the wall. For example, the grill fan may be manufactured byinjection molding. In this case, a method of molding a portioncorresponding to the TEM accommodating part 53 may be applied with theinjection molding. On the other hand, when a rear boundary of thestorage space is defined by the inner case 12 and it is difficult tomold a shape of the TEM accommodating part 53 in the process of moldingthe inner case 12, a method of manufacturing the TEM accommodating part53 as a separate part and assembling and fixing the TEM accommodatingpart 53 to the wall, as illustrated in FIG. 21, may be applied.

The TEM accommodating part 53 has a substantially rectangularparallelepiped shape protruding and extending forward from the frontsurface of the grill fan 51 (the rear of the TEM accommodating part 53is open toward the freezer compartment in which the evaporator isprovided), and a shape thereof when viewed from the front is asubstantially rectangular shape that is longer vertically than it ishorizontally. A grill portion 531 for discharging air cooled by the TEMassembly 100 is provided at a central portion of the rectangular shapewhen viewed from the front, and suction portions 533 are provided inupper and lower portions thereof. The suction portions 533 serve aspaths for suctioning air outside the suction portions 533 into an innerspace (that is, an inner space of a rectangular outer peripheral walldefining an outer shape of the TEM accommodating part 53 and a spacelocated behind the grill portion 531) of the TEM accommodating part 53.The inner space of the TEM accommodating part 53 is a space isolatedfrom the space provided in front of the grill fan 51 except that theinner space of the TEM accommodating part 53 is in conjunction with thespace provided in front of the TEM accommodating part 53 through thegrill portion 531 and the suction portion 533.

In order to prevent the cool air discharged from the grill portion 531from being immediately re-introduced into the suction portion 533disposed close to the grill portion 531, a discharge guide 532 having ashape of a partition extending forward between the grill portion 531 andthe suction portion 533 is provided between the grill portion 531 andthe suction portion 533. Providing the discharge guide 532 only in arange in which the grill portion 531 and the suction portion 533 areadjacent to each other is sufficient to prevent the air discharged fromthe grill portion 531 from being immediately re-introduced into thesuction portion 533.

However, when it is desired to further improve an effect a property inwhich the cool air discharged from the grill portion 531 is flowsforward, that is, straightness, the discharge guide 532 preferably has ashape which entirely surrounds the grill portion 531, as illustrated. Aflow cross section of the discharge guide 532 may be a square shape asillustrated, but may have a circular shape like the grill portion 531 ora blade shape of the fan disposed behind the grill portion. The flowcross section shape does not necessarily have a rectangular or circularflow cross section as long as it can improve straightness of the coolair while preventing the cool air discharged from the grill portion frombeing re-introduced into the suction portion, and may be modified invarious forms.

The suction portions 533 are not necessarily limited to being located atthe upper and lower positions of the cooling fan 190. That is, thesuction portions may be provided on left and right sides of the coolingfan 190, and the suction portions may be provided at one or moreselected positions of upper, lower, left, and right sides of the coolingfan.

As illustrated in FIGS. 6 to 9, the rear of the TEM accommodating part53 is open. The TEM assembly 100 is inserted in a forward direction intothe TEM accommodating part 53 from behind the grill fan 51 and isaccommodated therein.

A sensor mounting part 54 in which a sensor configured to sense atemperature and humidity of the very low temperature freezer compartment200 is installed is continuously provided at one side of the TEMaccommodating part 53 (see FIGS. 3, 5, and 10). A defrosting sensor isprovided in the sensor mounting part 54 to determine whether defrostingis required by sensing a defrosting time of a cold sink 120, which willbe described below. Preferably, the sensor mounting part is provided ata position at which a state of the very low temperature freezing spaceis expressed when the state of the very low temperature freezing spaceis measured. Since the suction portions according to the embodiment ofthe present invention are disposed at the upper and lower portions ofthe TEM accommodating part, the sensor mounting part being installed toavoid these positions is advantageous for a more accurate measurement.Therefore, in the present invention, the sensor mounting part 54 isdesigned to be installed on a side surface of the TEM accommodating part53. Further, a through hole is provided in the sensor mounting part 54in the forward direction so that an air atmosphere in front of thesensor mounting part may be transmitted to an inner space of the sensormounting part 54 through the through hole.

Referring to FIGS. 7 to 11, a small space is present in the lowerportion of the TEM accommodating part 53 when the TEM assembly 100 isaccommodated therein. The space is the inner space of the TEMaccommodating part, which is provided behind a suction portion 5332provided in front of the space, and is a flow path of air introducedinto the inner space of the accommodating part through the suctionportion 5332. That is, the air introduced through the suction portion5332 passes through the small space provided in the lower portion of theTEM accommodating part 53, moves upward, and exchanges heat with thecold sink 120.

Referring to FIGS. 9 to 11, a drain slope 535 having a shape inclineddownward from the suction portion 5332 to a main body of the grill fan51 is provided at a bottom surface of the TEM accommodating part 53behind the suction portion 5332. The drain slope 535 represents thebottom surface of the TEM accommodating part 53 that is inclineddownward. A drain hole 536 is provided at a center of a lower end of thedrain slope 535. The cold sink 120 is disposed directly above the drainslope 535.

According to the structure, as defrosting is performed on condensedliquid water of the cold sink 120, water falling from the cold sink 120falls onto the drain slope 535, and the water falling onto the drainslope 535 flows downward along the downward inclined surface and movesto the drain hole 536. Finally, the water is drained downward along thedrain hole 536.

The drain slope 535 and the drain hole 536 are provided in a space whichis in conjunction with the very low temperature freezing space.Therefore, the water which falls from the cold sink 120 and a heatexchange pin 122 of the cold sink 120 onto the drain slope due todefrosting may be refrozen on the drain slope in a very low temperatureatmosphere and in the drain hole 536.

In consideration of this fact, a heating wire 537 is installed on thebottom surface and the drain hole to prevent the defrosted water frombeing refrozen. When the defrosting of the cold sink 120 disposed in theTEM accommodating part 53 is performed by a defrost sensor of the sensormounting part, the water which falls from the cold sink 120 onto thedrain slope 535 may flow along the inclined surface of the drain slope535 toward the drain hole 536 and may be guided to the drain hole 536without being frozen by heat generated by the heating wire 537. Further,since the heating wire extends to an inside of the drain hole 536, thedefrosted water which flows downward along the drain hole 536 is alsonot frozen and flows downward. The defrosted water which flows from thedrain hole 536 is collected into a drain tray for the evaporator 77 inthe freezer compartment, which is located behind the shroud, through ahole in the shroud located under the drain hole. Such a phenomenon inwhich water may not be drained in the very low temperature and isrefrozen in the drain slope and the drain hole may be prevented by theheat of the heating wire 537.

Hereinafter, a method of installing the very low temperature freezercompartment 200 will be described. Guide rails 212 extending in forwardand backward directions are provided on both ends of the very lowtemperature case 210 of the very low temperature freezer compartment200, as illustrated in FIGS. 3 and 6. Specifically, each of the guiderails 212 has a shape in which an upper guide part 212-1 and a lowerguide part 212-2, which are a pair of vertically spaced protrusions, areelongated in the forward and backward directions and protrude laterally.Accordingly, grooves having a shape recessed in the forward and backwarddirections are provided between the pair of protrusions. That is, theguide rails 212 protrude to have a cross section similar to a bracketshape.

Meanwhile, as illustrated in FIGS. 2A to 2C, the rails 15 having a shapecorresponding to the recessed space of the guide rail 212 and extendingin the forward and backward directions and protruding laterally areprovided on side surfaces of the inner case 12 of the freezercompartment 40 and side surfaces of the partition wall 42. The rails aremanufactured separately from the inner case 12 by injection molding tosecure shape accuracy and strength and may then be installed to becoupled to an inner surface of the inner case 12. The rails may be usedas pedestal structures when shelves or drawers are installed. Accordingto the present invention, the very low temperature freezer compartmentmay be installed using the rails. The rails 15 may be attached to aninner wall of a side surface of the freezer compartment and a sidesurface of the partition wall. Each of the rails 15 has a shape in whichan upper rail 15-1 and a lower rail 15-2, which are a pair of verticallyspaced protrusions, are elongated in the forward and backward directionsand protrude laterally, and protrudes to have a cross section similar toa bracket shape. Rear ends of the upper rail 15-1 and the lower rail15-2 are connected to each other to regulate insertion depths of theguide rails 212 of the very low temperature case. The guide rails 212and the rails 15 may be fastened to each other so that the lower guidepart 212-2 is mounted on the lower rail 15-2 and the upper guide part212-1 is mounted on the upper rail 15-1. According to the structure,since the guide rails 212 are vertically supported by the rails 15 intwo stages, the guide rails 212 and the rails 15 may be more firmlyfixed.

In this manner, when groove spaces of the guide rails 212 provided atboth of the ends of the very low temperature case 210 are inserted intothe rails 15 provided on the side surfaces of the inner case 12 of thefreezer compartment and the side surfaces of the partition wall 42 andthe very low temperature case 210 is pushed rearward and fixed, an innerspace of the very low temperature freezer compartment 200 faces the TEMaccommodating part 53 and the sensor mounting part 54, as illustrated inFIGS. 7 to 12. An opening 211 through which the TEM accommodating part53 and the sensor mounting part 54 are inserted is provided in a rear ofthe very low temperature case 210 of the very low temperature freezercompartment 200. An inner circumferential surface of the opening 211 isfitted to outer circumferential surfaces of the TEM accommodating part53 and the sensor mounting part 54.

In order to facilitate the fitting of these circumferential surfaces, aninner circumferential surface 534 of the TEM accommodating part 53, theouter circumferential surface of the sensor mounting part 54, and theinner circumferential surface of the opening 211 of the very lowtemperature case 210 may be manufactured to have a shape having aslightly inclined surface that gradually narrows toward a front thereofand gradually widens toward a rear thereof (see FIGS. 7 to 9). Since across-sectional area of a rear end of the opening of the very lowtemperature case is slightly greater than a cross-sectional area of afront end of each of the TEM accommodating part 53 and the sensormounting part 54 when the circumferential surfaces have such an inclinedsurface shape, the TEM accommodating part 53 and the sensor mountingpart 54 are naturally guided into the opening of the very lowtemperature case 210 and the insertion begins at an initial stage ofinsertion, and the cross-sectional area of each of the TEM accommodatingpart 53 and the sensor mounting part 54 coincides with thecross-sectional area of the opening 211 of the very low temperaturecase, and these parts are firmly fitted when the insertion is completed.

The TEM assembly 100 is inserted in the forward direction into the TEMaccommodating part 53 from behind the grill fan assembly 50 and isaccommodated and fixed therein. More particularly, referring to FIGS. 6to 10, first, on a front side of the TEM accommodating part 53, an outercircumferential surface of the cooling fan 190 in the form of a box fanis fixed to a front surface of the TEM accommodating part 53 by afastening means such as a screw in a state in which the outercircumferential surface of the cooling fan 190 faces an innercircumferential surface of the TEM accommodating part 53 and a positionthereof is regulated. The TEM assembly 100 is inserted in the forwarddirection from the rear of the grill fan assembly 50 to be disposedbehind the cooling fan 190, and is fastened and fixed to the grill fanassembly 50 by the fastening means such as a screw.

Only the grill fan 51 may be present or the grill fan 51 and the shroud56 may be present in an overlapping form at a portion of the grill fanassembly 50 at which the TEM assembly 100 is fixed. Alternatively, onlythe grill fan may be partially present and the grill fan and the shroudmay be present in the overlapping form at the remaining portion thereofat a portion of the portion of the grill fan assembly 50 at which theTEM assembly 100 is fixed. When the TEM assembly 100 is fixed to aportion at which the grill fan and the shroud overlap by a fixing meanssuch as a screw or the like, the TEM assembly 100 may be fixed at thesame time in a case in which the grill fan and the shroud are fixed toeach other so that convenience of assembly may be obtained, and the TEMassembly 100 may be fixed to a firmer point by the grill fan and theshroud being stacked.

A spacer 111 extends rearward in the TEM assembly 100, and an end of thespacer 111 is in contact with the inner case 12. That is, the spacer 111is supported by the inner case 12 and functions to support the TEMassembly 100 to be maintained at a position spaced forward from theinner case 12. Since the end of the spacer 111 is fixed to the innercase 12 as described above, the TEM assembly 100 is maintained at aposition that is clearly spaced from the inner case 12, and thus heatradiation efficiency of a heat generating portion of the TEM assembly100 is further improved.

Meanwhile, as will be described below, a flow path through which therefrigerant passes is provided in the heat sink 150 of the TEM assembly100, and an inlet pipe 151 and an outlet pipe 152 for introduction anddischarge of the refrigerant are provided in the heat sink. Each of theinlet pipe and the outlet pipe of the refrigerant, which are provided inthe heat sink 150 of the TEM assembly in an assembling process of arefrigerator, should be welded to a refrigerant pipe through which therefrigerant flows in the refrigeration cycle cooling system 70 of therefrigerator. Specifically, the inlet pipe 151 may be connected to arear end of the condenser, that is, a rear of an expansion device suchas a capillary tube or the like, and the outlet pipe 152 may beconnected to a front of the evaporator.

In the TEM assembly 100, since the components illustrated in FIG. 13,which will be described below, are secured and fixed in the form of anassembled module with a predetermined distance from the inner case 12 bythe spacer 111, a worker may more easily perform a welding task of therefrigerant pipe in the space secured by the spacer 111, the grill fanassembly 50 may be installed in a back portion of the freezercompartment after the welding task of the refrigerant pipe, and thegrill fan assembly and the TEM assembly 100 may be fixed. The spacer 111may be fixed to the inner case 12 by a screw or the like or may be fixedto the inner case 12 via a method in which a hole provided in the rearof the spacer 111 is fitted to the protrusion protruding from the innercase 12.

The very low temperature case 210 has a housing structure having anopening at the front and the opening 211 formed at a portion of the rearthereof and having a substantially rectangular parallelepiped shape, andthe guide rails 212 extending in the forward and backward directions areprovided on left and right side surfaces of the very low temperaturecase 210 as described above. The very low temperature case 210 includesan outer case 213 facing the space of the freezer compartment and aninner case 214, which is coupled to the outer case 213, inside the outercase 213 and defining a size with a predetermined size with the outercase 213. The heat insulating material 80 is provided in the spacebetween the outer case 213 and the inner case 214 to insulate heat in agap between a space inside the very low temperature freezer compartment200 and the space of the freezer compartment 40. A foam heat insulatingmaterial 81 such as polyurethane or the like may be used as the heatinsulating material, and the foam heat insulating material functions tofix the outer case and the inner case in addition to a function of heatinsulation. The space between the outer case 213 and the inner case 214may be filled with the heat insulating material through a foam inlet 218(see FIG. 6) provided in the rear of the very low temperature case 210.After injection, the foam inlet 218 may be closed with a lid (notillustrated) or the like. A vacuum insulated panel 82 having betterinsulation efficiency may be further applied to a wall of the very lowtemperature case which should have a thin thickness.

The open front of the very low temperature case 210 is opened and closedby the very low temperature compartment door 220. The very lowtemperature compartment door 220 has a space with a predetermined sizethereinside, and the heat insulating material is provided in the spaceto insulate heat in a gap between the space inside the very lowtemperature freezer compartment 200 and the space of the freezercompartment 40. The very low temperature compartment door 220 maypreferably have a certain level of thickness for a grip feeling of auser, and the foam heat insulating material may be foamed in an insideof a hollow to secure rigidity.

A very low temperature tray 226 accommodated in an inner space of thevery low temperature case 210 is fixedly installed at the rear of thevery low temperature compartment door 220. The very low temperature tray226 may be configured to move integrally with the very low temperaturecompartment door 220. When the very low temperature compartment door 220is withdrawn in the forward direction, the very low temperature tray 226may be slid and withdrawn in the forward direction from the very lowtemperature case 210. The very low temperature compartment door 220 maybe guided by an outer rail provided on a lower or bottom surface of thevery low temperature case 210, and may be slid forward and backward.

An open groove 227 having a shape which is open to allow cool air toflow into the very low temperature tray 226 when the cool air cooled inthe TEM assembly 100 is introduced into the open groove 227 in theforward direction by the cooling fan 190 is provided at a rear wall ofthe very low temperature tray 226. The shape of the open groove 227corresponds to that of the TEM accommodating part 53, as illustrated inFIGS. 8 and 12. When the very low temperature freezer compartment 200 isinstalled in the freezer compartment 40, the open groove 227 faces theTEM accommodating part 53 so that low temperature cool air suppliedforward from the TEM accommodating part 53 by the cooling fan 190 may besmoothly introduced into an inner space of the very low temperature tray226.

Meanwhile, referring to FIG. 7, an upper surface of the very lowtemperature case 210 is slightly spaced apart from a bottom surface ofan upper member of the inner case 12, that is, a sealing surface.According to the present invention, the upper surface of the very lowtemperature case 210 and the bottom surface of the upper member of theinner case 12 cooperate with each other to implement a structure like aduct, and accordingly, air discharged from the cool air outlet pipe 52-2at an upper end of the grill fan 51 is guided forward along a structuresuch as the above-described duct and flows smoothly. Therefore, evenwhen the very low temperature case 210 is installed, cool air may alsosmoothly reach the door basket 27 provided in an upper portion of aninside of the freezer compartment door 22.

A thickness of an upper wall of the very low temperature case 210 shouldbe made thin to implement a structure like the above-described duct.That is, the thickness of the upper wall of the very low temperaturecase 210 should be made thin so that an inner volume of the very lowtemperature case may be secured and a structure like the duct may beimplemented. In this respect, in the present invention, the thickness ofthe upper member of the very low temperature case is made thin byfoaming the foam heat insulating material 81 in the remaining space in astate in which the vacuum insulated panel 82 is embedded inside theupper member of the very low temperature case. The foam heat insulatingmaterial functions to fill the space inside between the outer case andthe inner case which are not filled by the vacuum insulated panel, andfunctions to further improve a mounting force of the outer case and theinner case as well as heat insulation.

In addition, since the cool air outlet pipe 52-4 located near a centerof a height of the grill fan 51 is disposed below the very lowtemperature case 210, the cool air discharged through the cool airoutlet pipe 52-4 may also smoothly flow forward.

[Structure and Installation Structure of TEM Assembly]

FIG. 13 is an exploded perspective view of the TEM assembly according tothe present invention.

The TEM assembly 100 is an assembly in which the cold sink 120, thethermoelectric element 130, the heat insulating material 140, and theheat sink 150 are stacked and installed in a module housing 110 to forma module.

The thermoelectric element 130 is an element using a Peltier effect. ThePeltier effect refers to a phenomenon in which, when a direct current(DC) voltage is applied to ends of two different elements, heat isabsorbed on one side and is generated on the other side according to adirection of the current.

The thermoelectric element has a structure in which an N-typesemiconductor material in which electrons are main carriers and a P-typesemiconductor material in which holes are main carriers are alternatelyconnected in series. An electrode portion for allowing a current to flowfrom the P-type semiconductor material to the N-type semiconductormaterial is disposed on a first surface relative to any one direction inwhich the current flows, and an electrode portion for allowing a currentto flow from the N-type semiconductor material to the P-typesemiconductor material is disposed on a second surface. Therefore, whenthe current is supplied in a first direction, the first surface is aheat-absorbing surface and the second surface is a heat-generatingsurface, and when the current is supplied in a second direction oppositethe first direction, the first surface is the heat-generating surfaceand the second surface is the heat-absorbing surface.

According to the present invention, since the TEM assembly 100 isinserted in the forward direction from the rear of the grill fanassembly 50 and fixed and the very low temperature freezer compartment200 is provided in front of the TEM assembly 100, heat may be absorbedat a surface forming the front of the thermoelectric element, that is, asurface facing the very low temperature freezer compartment 200, andheat may be generated at a surface forming the rear of thethermoelectric element, that is, a surface facing opposite the very lowtemperature freezer compartment 200 or a surface opposite in a directionin which the very low temperature freezer compartment 200 is viewed.When current is supplied in the thermoelectric element in the firstdirection such that heat is absorbed at the surface facing the very lowtemperature freezer compartment and heat is generated at the surfaceopposite thereto, the very low temperature freezer compartment may becooled.

In the embodiment of the present invention, the thermoelectric element130 has the same shape as a flat plate having a front surface and a rearsurface, and, for example, the front surface is a heat-absorbing surface130 a and the rear surface is a heat-generating surface 130 b. DC powersupplied to the thermoelectric element 130 causes the Peltier effect,and thus heat of the heat-absorbing surface 130 a of the thermoelectricelement 130 moves toward the heat-generating surface 130 b. Therefore,the front surface of the thermoelectric element 130 is a cold surfaceand a rear surface thereof is a heat-generating portion. That is, thePeltier effect causes heat inside the very low temperature freezercompartment 200 is discharged outside the very low temperature freezercompartment 200. Power supplied to the thermoelectric element 130 may beapplied to the thermoelectric element through conducting wires 132provided in the thermoelectric element 130.

The cold sink 120 is stacked on the front surface of the thermoelectricelement 130, that is, on the heat-absorbing surface 130 a facing thevery low temperature freezer compartment 200 to be in contact therewith.The cold sink 120 may be made of a metal material such as aluminumhaving a high thermal conductivity or an alloy material, and a pluralityof heat exchange pins 122 extending in a vertical direction are formedon a front surface of the cold sink 120 to be spaced apart from eachother. The heat exchange pins 122 are preferably elongated verticallyand continuously extended without breaking. This is to secure a propertyin which water melted in the cold sink during defrosting of the coldsink 120 flows smoothly along a continuous form of the heat exchangepins extending vertically in the direction of gravity. The heat exchangepins 122 preferably have enough of an interval to prevent a downwardflow of water formed between two adjacent heat exchange pins 122 due tosurface tension.

Air inside the very low temperature freezer compartment flows andperforms a heat exchange in the cold sink 120 attached to theheat-absorbing surface of the thermoelectric element. A phenomenon inwhich moisture contained in air is frozen on a colder surface of thecold sink when food is cooled inside the very low temperature freezercompartment occurs. In order to remove such frozen water, power isapplied in a current supplying direction, that is, in theabove-described second direction opposite the first direction. Theheat-absorbing surface and the heat-generating surface of thethermoelectric element 130 are changed relative to the case in which thepower is applied in the first direction. Accordingly, a surface of thethermoelectric element in contact with the heat sink acts as theheat-absorbing surface and a surface of the thermoelectric element incontact with the cold sink acts as the heat-generating surface.Therefore, the frozen water which was frozen in the cold sink is meltedand flows downward in the direction of gravity, and thus defrosting isperformed. That is, according to the present invention, whencondensation occurs in the cold sink 120 and defrosting is required,defrosting may be performed by applying a current in the seconddirection opposite the first direction, which is a direction of acurrent applied to cause a very low temperature cooling action.

The heat sink 150 is stacked to be in contact with the rear surface ofthe thermoelectric element 130, that is, on the heat-generating surface130 b which is opposite the direction in which the very low temperaturefreezer compartment 200 is disposed. The heat sink 150 is configured torapidly dissipate or discharge heat generated on the heat-generatingsurface 130 b by the Peltier effect, and a portion corresponding to theevaporator 77 of the refrigeration cycle cooling system 70 used forcooling the refrigerator may be configured as the heat sink 150. Thatis, when a process in which a low-temperature and low-pressure liquidrefrigerant passing through the expansion device 75 in the refrigerationcycle absorbs heat or evaporates while absorbing heat is performed inthe heat sink 150, the heat generated on the heat-generating surface 130b of the thermoelectric element 130 is absorbed by the refrigerant inthe refrigeration cycle or is absorbed while the refrigerant isevaporated, and thus the heat of the heat-generating surface 130 b maybe immediately cooled.

Since the above-described cold sink 120 and the heat sink 150 arestacked by the thermoelectric element 130 having a flat shape beinginterposed therebetween, it is necessary to isolate heat therebetween.Therefore, the heat insulating material 140, which surrounds a peripheryof the thermoelectric element 130 and fills a gap between the cold sink120 and the heat sink 150, is stacked on the TEM assembly 100 of thepresent invention. That is, an area of the cold sink 120 is greater thanthat of the thermoelectric element 130, and is substantially the same asthat of each of the thermoelectric element 130 and the heat insulatingmaterial 140. Similarly, an area of the heat sink 150 is greater thanthat of the thermoelectric element 130, and is substantially the same asthat of each of the thermoelectric element 130 and the heat insulatingmaterial 140.

Meanwhile, sizes of the cold sink 120 and the heat sink 150 are notnecessarily the same as each other, and the heat sink 150 may beconfigured to be larger to effectively discharge heat.

However, according to the present invention, the refrigerant of therefrigeration cycle cooling system 70 flows through the heat sink sothat the heat of the heat sink 150 is instantly, reliably, andefficiently discharged, and the refrigerant is evaporated in the heatsink and rapidly absorbs the heat from the heat-generating surface ofthe thermoelectric element 130 as vaporization heat by allowing the flowpath of the refrigerant to be disposed over the entire area of the heatsink. That is, the heat sink illustrated in the present invention isdesigned to have a size sufficient to immediately absorb and dischargeheat generated by the thermoelectric element, and the cold sink may havea size smaller than the above size. However, in the present invention,it should be noted that heat exchange efficiency at the cold sink isfurther increased by the size of the cold sink being increased inconsideration of a heat exchange between a gas and a solid beingperformed at the cold sink and a heat exchange between a liquid and asolid being performed at the heat sink. In the embodiment of the presentinvention, in order to increase the size of the cold sink, the cold sinkis illustrated as being designed to have a size corresponding to that ofthe heat sink in consideration of compactness of the TEM assembly.However, the cold sink may be configured to be larger than the heat sinkto further increase heat exchange efficiency of the cold sink.

The cold sink 120, the thermoelectric element 130, the heat insulatingmaterial 140, and the heat sink 150 are inserted and fixed into anaccommodating groove 113 of the module housing 110 in a state in whichthey are closely stacked by a tightening means such as a screw. A flange112 having an outwardly extending shape is provided at an edge of afront end of the accommodating groove 113 of the module housing 110. Theflange 112 is a portion in which the TEM assembly 100 is closely fixedto the grill fan assembly 50.

Hereinafter, an installation structure of the TEM assembly 100 will bedescribed in detail with reference to FIGS. 16A to 17B. FIGS. 16A and16B are cross-sectional views taken along line I-I of FIG. 6, and FIGS.17A and 17B are enlarged perspective views of a portion J of FIG. 8 whenviewed from the rear.

As described above, the grill fan assembly 50 includes the TEMaccommodating part 53 which accommodates the TEM assembly 100. The TEMaccommodating part 53 is provided in a shape protruding forward from thegrill fan 51, and the TEM assembly 100 is fitted into the TEMaccommodating part 53 behind the grill fan assembly.

Referring to FIG. 16A, a portion of the shroud 56 overlaps the rear ofthe TEM accommodating part 53 of the grill fan 51. More particularly, anabutting surface 561 of the shroud abuts and is fixed to the rearsurface of the grill fan 51 which surrounds the TEM accommodating part53. A TEM insertion hole 563 is provided around an inner edge of theabutting surface 561 of the shroud, and a portion opened by the TEMinsertion hole 563 is a path which is in conjunction with the innerspace of the TEM accommodating part 53 behind the grill fan assembly 50.Referring to FIG. 17A, the above-described TEM assembly 100 is fixed ata position at which the rear surface of the grill fan 51 and theabutting surface 561 of the shroud 56 overlap. Generally, the grill fan51 and the shroud 56 are made of an injection molded synthetic resin,and are manufactured in a plate form. The synthetic resin in a plateform is sufficient as a structure for partitioning a space. However,there is a concern that rigidity may be insufficient to fix a specificstructure on a corresponding plate. However, according to the presentinvention, since the TEM assembly 100 is fixed at a position at whichthe rear surface of the grill fan 51 and the abutting surface 561 of theshroud overlap, rigidity for fixing and supporting the TEM assembly 100may be sufficiently secured.

As a modified example, the TEM assembly 100 illustrated in each of FIGS.16B and 17B may be in direct contact with the rear surface of the grillfan and fixed thereto. In the modified example, a structure in which theflange 112 of the TEM assembly 100 is directly fixed to the rear surfaceof the grill fan 51 is illustrated.

A rear rib 511 extending rearward is provided on the rear surface of thegrill fan 51. The rear rib 511 is provided on an outer periphery of therear surface of the grill fan 51 slightly spaced apart from the TEMaccommodating part 53. More particularly, the rear rib 511 is formed atthe position at which the rear surface of the grill fan and the abuttingsurface 561 of the shroud overlap, or is formed at a side fartheroutward from the TEM accommodating part 53 than a position at which theTEM assembly 100 is installed.

In addition, similarly, a rib abutting surface 562 extending rearward tocome into contact with the inner surface of the rear rib 511 is providedon an outer circumferential surface of the abutting surface 561 of theshroud. That is, the abutting surface 561 and the rib abutting surface562 are bent to form a stepped shape. Therefore, the abutting surface561 of the shroud and the rib abutting surface 562 are brought intocontact with the rear surface of the grill fan 51 and the rear rib 511in an L shape.

In the rear rib 511 and the rib abutting surface 562, rigidity may befurther secured due to a characteristic of the stepped shape andassembly of the TEM assembly 100 fixed to a rear surface of the abuttingsurface 561 of the shroud may be further facilitated. That is, when anouter edge of the flange 112 provided in the module housing 110 of theTEM assembly 100 is manufactured to be merged to some extent, that is,slightly, with an inside of the rib abutting surface 562, an outercircumferential surface of the flange 112 of the TEM assembly 100 isloosely fitted into the stepped shape by the rib abutting surface 562when the TEM assembly 100 is fixed to the grill fan assembly 50, andthus the TEM assembly 100 may be easily fixed to the grill fan assembly50 while accurately regulating a position of the TEM assembly 100. Asillustrated in FIGS. 10, 17A, and 17B, when a bent surface 112 a isprovided to extend rearward from the outer edge of the flange 112, thebent surface 112 a comes into contact with an inner circumferentialsurface of the rib abutting surface 562, and thus the position thereofis more securely regulated and rigidity of the flange 112 is reinforced.

The above-described spacer 111 may be fixed to the inner case 12 by afixing means such as a screw or using a groove-boss press-fit method ina state in which the spacer 111 extends rearward from the flange 112 andcomes into contact with the inner case 12 of the refrigerator main body10. Therefore, the module housing 110 firmly fixes the TEM assembly 100to both the grill fan assembly 50 and the inner case 12. Since thespacer 111 of the module housing 110 fixes the TEM assembly 100 in astate of being spaced apart from the inner case 12, heat radiationefficiency of the heat sink is increased and a working space sufficientfor welding the inlet pipe and the outlet pipe of a refrigerant passingthrough the thermoelectric element to the refrigerant pipe of therefrigeration cycle cooling system 70 is secured, as described above.

The cooling fan 190 installed at a front-most portion of the TEMassembly 100 may be configured separately from the TEM assembly 100 bybeing fastened and fixed to the TEM accommodating part 53 of the grillfan 51, as in the embodiment of the present invention illustrated in thedrawing, or may become one component of the TEM assembly 100 by beingintegrated with the TEM assembly 100 in such a manner that the coolingfan 190 is fixed to the cold sink 120 at a predetermined interval by afastening means such as a screw. When the cooling fan 190 is rotated,the cooling fan 190 pressurizes air and allows the air to flow toward afront side, that is, toward the very low temperature freezer compartment200. Therefore, air behind the cooling fan 190 is discharged forward bythe cooling fan 190 so that a space behind the cooling fan 190 isre-filled with air in the very low temperature freezer compartment 200.Air re-filled in the TEM accommodating part 53 exchanges heat with thecold sink 120 and is cooled to a very low temperature.

According to the refrigerator having the very low temperature freezercompartment according to the present invention, the thermoelectricelement 130 and the heat sink 150 of the TEM assembly 100 are disposedfurther rearward from a surface of the grill fan 51 forming the rearwall of the freezer compartment 40, and thus the heat generated in thethermoelectric element 130 may be intrinsically blocked from beingintroduced into the freezer compartment 40.

Referring to FIGS. 7, 10, and 16A to 17B, the space of the freezercompartment 40 is defined as a front space of the grill fan 51, and thevery low temperature freezer compartment 200 is defined as an innerspace distinguished by the grill fan 51, the very low temperature case210, and the very low temperature compartment door 220. The TEM assembly100 of the present invention is disposed at the rear of the very lowtemperature case 210. Specifically, the thermoelectric element 130 andthe heat insulating material 140 of the TEM assembly 100 and the heatsink 150 located behind the heat insulating material 140 are locatedfurther rearward from a rear cross section (D-D of FIGS. 7 and 10) ofthe freezer compartment 40 defined by the grill fan 51. That is, thethermoelectric element 130 and the heat sink 150 located behind thethermoelectric element 130 are located between the rear of the grill fan51 and the inner case 12. More particularly, the thermoelectric element130 and the heat sink 150 located behind the thermoelectric element 130are located behind the grill fan and are disposed in a heat exchangespace (the freezer compartment which is a space defined separately fromthe freezer compartment) including an evaporator 77 a.

According to an arrangement position of the TEM assembly 100, the heatgenerated in the heat-generating surface 130 b and the heat sink 150 isfundamentally blocked from affecting a temperature of the space of thefreezer compartment 40, and thus heat loss of the inner space of thefreezer compartment 40 due to the thermoelectric element 130 may beprevented. That is, in the present invention, the TEM assembly 100 isinstalled in a space separated from the very low temperature freezercompartment installed in the freezer compartment by the TEM assembly 100being installed behind the grill fan 51, which is a wall separating thefreezer compartment from the freezer compartment, and thus heat loss ofthe freezer compartment may be prevented while very low temperaturecooling is smoothly performed.

The accommodating groove 113 of the module housing 110 is provided toextend rearward relative to the flange 112. The flange 112 is fixed tothe grill fan 51 defining a rear surface of the freezer compartment withthe shroud 56 interposed therebetween. However, as described above, thethermoelectric element and the heat sink of the TEM assembly arepreferably disposed in a separate space from the freezer compartment.

Accordingly, in the present invention, the accommodating groove 113 isformed to extend rearward relative to the flange 112, configurations ofthe assembly are accommodated in the accommodating groove 113 in theorder of the heat sink, the thermoelectric element, and the cold sink,and thus the heat sink and the thermoelectric element are located at arear of the space defined as the freezer compartment.

In contrast to the arrangement of the thermoelectric element and theheat sink, the very low temperature freezer compartment 200 is disposedinside the freezer compartment. The cold sink 120 of the TEM assembly100 is also disposed in front of the rear cross section (D-D of FIGS. 7and 10) of the freezer compartment 40. The cold sink 120 may be disposedin front of the rear cross section of the freezer compartment as aportion colder than the freezer compartment, and is preferably disposedas close as possible to the very low temperature freezer compartment 200in terms of cooling of the very low temperature freezer compartment.

That is, according to the present invention, the very low temperaturefreezer compartment 200 and the cold sink 120 are disposed in front ofthe rear cross section of the freezer compartment defined by the grillfan, that is, in the freezer compartment, and the thermoelectric element130 and the heat sink 150 are disposed behind the rear cross section ofthe freezer compartment, that is, in the freezer compartment.

FIG. 14 is a front perspective view illustrating a modified example ofthe TEM assembly according to the present invention, and FIG. 15 is arear perspective view of the modified example of FIG. 14.

The modified example illustrated in FIGS. 14 and 15 is different fromthe TEM assembly of FIG. 13 in that two spacers 111 are provided at anupper portion of the TEM assembly. That is, according to the modifiedexample, since there are three spaces which are not disposed in astraight line, a space fixing force for the inner case 12 may be furthersecured in comparison with the TEM assembly including only two spacersabove and below.

Further, according to the modified example, holes or grooves areprovided in the rear of the spacer, and protrusions which may be fittedto such holes or grooves are provided at the inner case 12 so that thespacer 111 may be fixed to the inner case 12 in a groove-boss press-fitmethod, which makes installation more convenient. This method may be asimpler method than a method of fastening the spacer and the inner casewith a screw through a screw hole of the spacer 111 illustrated in FIGS.17A and 17B.

Meanwhile, the very low temperature freezer compartment 200 may beinstalled in the refrigerator compartment 30. Referring to FIG. 21, awall defining the rear boundary of the storage space of the refrigeratorcompartment 30 may be the inner case 12. Further, although notillustrated, a multi-duct for uniformly distributing cold air to therefrigerator compartment may form at least a portion of the walldefining the rear boundary of the storage space of the refrigeratorcompartment.

The space between the inner case 12 and the outer case 11 may be filledwith a foam heat insulating material, and thus a space in which thethermoelectric module 100 may be disposed may be secured when the foamheat insulating material is foamed. The drain hole 536 through whichdefrosted water may be drained is formed when the foam heat insulatingmaterial is foamed. In addition, the refrigerant pipe connected to theheat sink 150 of the TEM assembly 100 may be filled with the foam heatinsulating material while being embedded therein. Similarly, theembedded refrigerant pipe may be connected to the refrigerant inletpipes 151 and 152 of the heat sink 150 by welding or the like in theprocess of installing the TEM assembly 100.

The flange 112 of the module housing 110 may be fixed to a front surfaceof the inner case 12 in the process of disposing the TEM assembly 100 ata proper position. The TEM accommodating part 53 manufactured with aseparate part may be fixed to the front surface of the inner case 12. Inthis case, the TEM accommodating part 53 and the flange 112 of themodule housing 110 may be fixed to the inner case 12 to overlap eachother as illustrated. Although not illustrated, the TEM accommodatingpart 53 and the flange 112 of the module housing 110 may be fixed to theinner case 12 so as not to overlap each other. The TEM accommodatingpart 53 is integrated by being fixed to the inner case 12.

A rear surface 211-1 (see FIG. 6) of the very low temperature case 210of the very low temperature freezer compartment 200 may be in closecontact with the front of the inner case 12, which is a wall defining arear surface of the storage space. The rear surface 211-1 being in closecontact with the inner case includes all of a case in which the rearsurface of the very low temperature case is in direct contact with thefront surface of the inner case, a case in which the rear-surface of thevery low temperature case is in direct contact with a surface of the TEMaccommodating part 53 installed on the front surface of the inner caseto come into contact the inner case, and the like.

An inner circumferential surface 211 a of the opening 211 provided inthe rear surface of the very low temperature case 210 may be in closecontact with the outer circumferential surface 534 of the TEMaccommodating part 53.

Even with the above-described structure, the thermoelectric element 130and the heat sink 150 of the TEM assembly 100 are disposed furtherrearward from the wall (the inner case 12) defining the rear boundaryD-D of the storage space (the refrigerator compartment 30) cooled by therefrigeration cycle cooling system, and thus the heat exchange pin 122of the cold sink 120 is located in front of the rear boundary D-D whilean influence of the heat generated in the TEM assembly 100 on therefrigerator compartment 30 is minimized so that cooling efficiency ofthe very low temperature freezer compartment 200 may be maintained to behigh.

[Refrigeration Cycle Cooling System for Implementing Extremely LowTemperature of Very Low Temperature Freezer Compartment]

FIG. 18 is a view illustrating a refrigeration cycle applied to therefrigerator according to the present invention, and FIG. 19 is a viewillustrating another embodiment of the refrigeration cycle applied tothe refrigerator according to the present invention.

The refrigeration cycle cooling system 70 of the refrigerator accordingto the present invention is a device configured to discharge heat insidethe freezer compartment outside the refrigerator via a refrigerantpassing through a thermodynamic cycle of evaporation, compression,condensation, and expansion. The refrigeration cycle cooling system ofthe present invention includes the evaporator 77 in which a liquid phaserefrigerant in a low-pressure atmosphere is evaporated by exchangingheat with air in the freezer compartment (the space between the grillfan assembly and the inner housing), the compressor 71 in which agaseous refrigerant vaporized in the evaporator is pressurized and isdischarged as a high temperature and high pressure gaseous refrigerant,the condenser 73 in which the high-temperature and high-pressure gaseousrefrigerant discharged from the compressor exchanges heat with airoutside the refrigerator (the machine compartment), is condensed, andheat is discharged therefrom, and the expansion device 75 such as acapillary tube in which the refrigerant condensed in the condenser 73 islowered to be in a low temperature atmosphere. A low-temperature andlow-pressure refrigerant in the liquid phase whose pressure is loweredin the expansion device 75 is introduced back into the evaporator.

According to the present invention, since the heat of the heat sink 150of the TEM assembly 100 should be rapidly cooled, before alow-temperature and low-pressure refrigerant in the liquid phase whosepressure and temperature are lowered is introduced into the evaporator77 after passing through the expansion device 75, the refrigerant isconfigured to first pass through the heat sink 150 of the TEM assembly100.

FIG. 20 is an enlarged perspective view illustrating a state in which arefrigerant pipe behind a capillary tube of a refrigeration cycle and acapillary tube in front of an evaporator are connected to therefrigerant inlet pipe 151 and the refrigerant outlet pipe 152 of theTEM assembly fixed to the grill fan assembly, respectively. Asillustrated in FIG. 20, the refrigerant inlet pipe 151, which is exposedto behind the module housing through an open hole provided at a lowerportion of the module housing 110 of the TEM assembly 100, and moreparticularly, at a lower portion of the accommodating groove, isconnected to a refrigerant pipe of a refrigeration cycle passing throughan expansion device such as a capillary tube. The refrigerant outletpipe 152 exposed behind the module housing is connected to a refrigerantpipe introduced into the evaporator. Therefore, a refrigerant passingthrough the capillary tube is introduced into the heat sink 150 throughthe refrigerant inlet pipe 151 to cool or absorb heat of theheat-generating surface of the thermoelectric element 130, and passesthrough the refrigerant outlet pipe 152 to be introduced into theevaporator 77.

The liquid phase refrigerant passes through the heat sink 150 whilerapidly absorbing heat generated by the heat-generating surface 130 b ofthe thermoelectric element 130 via the heat sink 150 using a heatconduction method. Therefore, the heat of the heat sink 150 is rapidlycooled by the refrigerant circulating through the heat sink.

This process will be described in detail with reference to FIG. 18. Thecompressor 71 pressurizes the low-temperature and low-pressure gaseousrefrigerant to discharge a high-temperature and high-pressure gaseousrefrigerant. Heat is generated in the condenser 73 and the refrigerantis condensed, that is, is liquefied. As described above, the compressor71 and the condenser 73 are disposed in the machine compartment of therefrigerator.

The high-temperature and high-pressure liquid refrigerant which ispassed through the condenser 73 and liquefied is introduced into theevaporator 77 while being depressurized through the expansion device 75such as a capillary tube. In the evaporator 77, the refrigerant absorbsthe surrounding heat and evaporates. According to the embodiment of thepresent invention illustrated in FIG. 18, the refrigerant passingthrough the condenser 73 is branched to a refrigerator compartmentevaporator 77 b or a freezer compartment evaporator 77 a. In this case,the heat sink 150 of the TEM assembly 100 is provided in front of thefreezer compartment evaporator 77 a on a flow path of the refrigerantand is disposed behind the expansion device 75.

The very low temperature freezer compartment 200 is a space in which atemperature of −50° C. should be maintained, and the heat-generatingsurface 130 b of the thermoelectric element 130 should be maintained tobe very cool so that the heat-absorbing surface 130 a is smoothlymaintained to be cooler than the heat-generating surface 130 b.Therefore, the heat sink 150 through which the refrigerant passes isdisposed in front of the freezer compartment evaporator 77 a on the flowpath of the refrigerant so that a coldest state may be maintained.Specifically, since the heat sink 150 is in direct contact with thethermoelectric element 130 and absorbs the heat generated by thethermoelectric element 130 via a heat conductor such as a metal in aconductive manner, the heat-generating surface 130 b of thethermoelectric element 130 may be reliably cooled.

Meanwhile, when it is desired that the very low temperature freezercompartment 200 be used at a temperature of −20° C. like a typicalfreezer compartment without being cooled at a very low temperature of−50° C., the very low temperature freezer compartment 200 may be used asa general freezer compartment only by not supplying power to thethermoelectric element 130. In this case, when power is not applied tothe thermoelectric element 130, heat absorption and heat generation donot occur in the heat sink of the thermoelectric element. Therefore, therefrigerant passing through the heat sink 150 is introduced into thefreezer compartment evaporator 77 a in as a liquid refrigerant that doesnot absorb heat and is not evaporated.

A hole through which defrosted water generated by the above-describeddefrosting of the cold sink 120 is drained, that is, the drain hole 536,is provided in the TEM accommodating part 53 and is in conjunction withthe space between the grill fan 51 and the shroud 56 and/or the spacebetween the grill fan assembly 50 and the inner case 12. Therefore, whenthe cooling fan 190 is operated without power being supplied to thethermoelectric element 130, cool air in the space between the grill fan51 and the shroud 56 and/or the space between the grill fan assembly 50and the inner case 12 may be introduced into the TEM accommodating part53 and discharged into the very low temperature freezer compartment 200by the cooling fan 190. Further, in order to promote introduction ofcool air in the space between the grill fan 51 and the shroud 56 and/orthe space between the grill fan assembly 50 and the inner case 12 intothe TEM accommodating part 53, an additional fan (not illustrated) maybe further provided. In addition, a damper structure may be added inorder to selectively supply air cooled by the refrigeration cyclecooling system 70 when the very low temperature freezer compartment isused as a general freezer compartment.

That is, cool air generated in a refrigeration cycle cooling systemusing a general compression method is supplied to the freezercompartment and the refrigerator compartment of the refrigerator of thepresent invention. When the very low temperature freezer compartment isoperated, the refrigerant passing through the expansion device 75 passesthrough the heat sink 150 of the TEM assembly 100, rapidly absorbs theheat generated in the heat-generating surface of the thermoelectricelement 130, rapidly discharges the heat generated in theheat-generating surface of the thermoelectric element 130, and thenenters the evaporator 77 a.

The refrigeration cycle cooling system 70 in FIG. 19, which is amodified example of the refrigeration cycle cooling system in FIG. 18,is different from the refrigeration cycle cooling system 70 illustratedin FIG. 18 in that the refrigeration cycle cooling system 70 has astructure in which cooling is performed in the freezer compartment andthe refrigerator compartment using one evaporator 77 without a separateevaporator 77 b for the refrigerator compartment. That is, there is nodifference between the refrigeration cycle structure of FIG. 19 and thatof FIG. 18 except that there is no need for a three-way valve, abackflow prevention valve, or the like, and there is no branch portionof the expansion device 75 and the evaporator 77 b on the refrigeratingcompartment. That is, according to the present invention, even in thecase of a refrigeration cycle in which cooling is performed using oneevaporator 77, the refrigerant is disposed so as to pass through theheat sink 150 of the TEM assembly 100 and exchange heat therewith at aposition corresponding to the front of the evaporator 77 or a rear ofthe expansion device 75, and thus the cooling of the heat-generatingsurface 130 b of the thermoelectric element 130 may be performed withthe highest priority.

[Operation of Very Low Temperature Freezer Compartment]

The very low temperature freezer compartment 200 may store food at atemperature lower than −20° C., which is a temperature of a generalfreezer compartment, and may be cooled down to a temperature of −50° C.However, such an extremely low temperature is intended to generate aquenching environment to prevent water from being drained from cells orseparating the cells, as described above, and a storage temperature maybe higher than the temperature of the quenching environment (−50° C.)after being quenched once.

Therefore, storing food after the food is quenched at the temperature ofthe quenching environment may result in energy consumption beingincreased. Therefore, in the present invention, food may be quenched ata temperature of −50° C. at the beginning of cooling and then maintainedat a slightly higher temperature (e.g., −45 to 40° C.) than thetemperature of −50° C., and thus power consumption may be reduced whilefreshness of a stored product is maintained.

Such operating conditions may be changed in various ways. For example,food may be quenched at a temperature of −50° C. at the beginning andthen maintained at a slightly higher temperature (e.g., −35 to 30° C.)than the temperature of −50° C., and thus freshness of a stored productmay be secured through the quenching, cooling time may be reduced, andpower consumption may be further reduced.

Further, the very low temperature freezer compartment may be operatedusing a concept of a fresh compartment in which an initial quenchingtemperature is set to about −35° C. without setting a temperature of−50° C., and then the temperature is continuously maintained at about−35° C.

An operation mode may be selected by a user. The selection of a very lowtemperature may be attributed to a characteristic of the TEM. That is,in a cooling method of a compressor and a refrigerant, it is difficultto abruptly change an operation mode and to finely control atemperature. However, since the TEM may finely control the temperatureof the very low temperature freezer compartment according to a currentapplied thereto, the above-described various operation modes arepossible.

[Arrangement and Operation of TEM Assembly]

The TEM assembly 100 is accommodated in the TEM accommodating part 53provided in the grill fan assembly 50. The cooling fan 190 is providedin front of the TEM assembly 100 in the TEM accommodating part. Thecooling fan 190 is closely fixed to a rear surface of a front surface ofthe TEM accommodating part 53. In the present invention, a structure inwhich the cooling fan 190 is fixed to the front surface of the TEMaccommodating part 53 by screws being passed through four cornersthereof is illustrated.

In the cooling fan 190 in the form of a box fan, a forwardly flatcircular air discharge surface 191 is provided, and the air dischargesurface 191 is in contact with the rear surface of the grill portion 531provided on the front surface of the TEM accommodating part 53. Thegrill portion 531 having a size corresponding to that of the airdischarge surface 191 prevents air discharged from the cooling fan 190from being discharged by the fan blade of the cooling fan 190 while theair discharged from the cooling fan 190 is smoothly discharged toprotect the fan. The cold sink 120 provided in front of the TEM assembly100 is disposed behind the cooling fan 190 in the form of a box fan.

According to the present invention, the discharge guide 532 in the formof a duct protruding forward from the grill portion 531 is formed at anedge of the grill portion 531 in contact with the air discharge surface191 of the cooling fan 190. The discharge guide 532 is illustrated asbeing formed to have a square cross-sectional shape corresponding tothat of the cooling fan 190 in the form of a square box fan. However, asdescribed above, the shape of the discharge guide 532 may be variouslymodified.

An end of the discharge guide 532 faces the open groove 227 provided inthe rear of the very low temperature tray 226. Therefore, the cool airdischarged through the discharge guide 532 is introduced into the verylow temperature tray 226, strongly flows forward, and uniformly coolsthe very low temperature freezing space.

The above-described suction portion 533, which is open in the forwarddirection, is disposed on substantially the same plane as the airdischarge surface, and the discharge guide 532 is disposed between theair discharge surface 191 of the cooling fan and the suction portion533. When the suction portion is disposed in front of the air dischargesurface, the air discharged from the air discharge surface isimmediately re-suctioned into the suction portion. Conversely, when thesuction portion is disposed behind the air discharge surface, a suctionforce of the suction portion is weakened and a circulating force of thecool air circulating in the very low temperature freezer compartment theinner space is weakened.

Further, the suction portion 533, which is open in the forwarddirection, is disposed at each of an upper portion and a lower portionof the air discharge surface. A suction portion 5331 located at theupper portion of the cooling fan 190 absorbs heat from the very lowtemperature freezer compartment 200 and suctions raising air. Thesuction portion 5332 located at the lower portion of the cooling fan 190is a path in which cool air discharged and supplied toward a frontsurface of the very low temperature tray 226 passes through the very lowtemperature tray 226 and is re-suctioned into the TEM accommodating part53 through a space h between a bottom surface of the very lowtemperature tray and a bottom surface of the very low temperature case210.

The space h between the bottom surface of the very low temperature trayand the bottom surface of the very low temperature case preferablyranges from 4 mm to 7 mm. When the space h is smaller than 4 mm, flowresistance of the cool air is increased, and the circulating flow of thecold air is lowered. Conversely, when the space h is greater than 7 mm,the circulating flow of the cold air hardly is improved, and a storagecapacity volume of the very low temperature tray 226 is reduced.

The air suctioned into the inner space of the TEM accommodating part 53through the suction portion 533 flows toward a negative pressure portiongenerated on the air suction surface of the cooling fan 190 in themiddle and comes into contact with the heat exchange pin 122 of the coldsink 120 to exchange heat therewith. Since the suction portions areprovided at the upper and lower sides, the flow of the cold air mainlyoccurs in the vertical direction even in the TEM accommodating part.Correspondingly, the heat exchange pin 122 of the cold sink 120 isformed in a vertically elongated shape.

[Sealing Structure of Grill Fan Assembly for Operating Very LowTemperature Freezer Compartment]

FIG. 22 is an enlarged cross-sectional view taken along line I-I of FIG.6, FIG. 23 is an enlarged perspective view of the portion J of FIG. 8when viewed from the rear, FIG. 24 is a side cross-sectional viewillustrating a state in which a very low temperature compartment doorand a very low temperature tray are withdrawn from the very lowtemperature case assembled in the grill fan assembly, FIG. 25 is anenlarged side cross-sectional view illustrating a state in which thevery low temperature compartment door is closed in the very lowtemperature case of FIG. 24, and FIG. 26 illustrates cross-sectionalviews taken along lines Q-Q and R-R of FIG. 24.

As described above, the grill fan assembly 50, and more particularly,the grill fan 51, includes the TEM accommodating part 53 whichaccommodates the TEM assembly 100. The TEM accommodating part 53 isprovided in a form protruding forward from the grill fan 51, and the TEMassembly 100 is fitted to the TEM accommodating part 53 in behind thegrill fan assembly.

A portion of the shroud 56 overlaps the rear of the TEM accommodatingpart 53 of the grill fan 51. More particularly, the abutting surface 561of the shroud is in contact with the rear surface of the grill fan 51,which surrounds the TEM accommodating part 53, and is fixed thereto. TheTEM insertion hole 563 is provided at an inner edge of the abuttingsurface 561 of the shroud, and a portion opened by the TEM insertionhole 563 is a path in conjunction with the inner space of the TEMaccommodating part 53 from the rear of the grill fan assembly 50.

The above-described TEM assembly 100 is fixed at a position at which therear surface of the grill fan 51 and the abutting surface 561 of theshroud 56 overlap. The grill fan 51 and the shroud 56 are usually madeof an injection molded synthetic resin, and are manufactured in a plateform. The synthetic resin in the plate form is sufficient as a structurefor partitioning a space. However, there is a concern in that rigiditymay be insufficient to fix a specific structure on a correspondingplate. However, according to the present invention, since the TEMassembly 100 is fixed at the position at which the rear surface of thegrill fan 51 and the abutting surface 561 of the shroud overlap,rigidity for fixing and supporting the TEM assembly 100 may besufficiently secured.

However, as described above, since the grill fan 51 and the abuttingsurface 561 of the shroud are in contact with each other at a peripheryof the TEM accommodating part 53, a gap defined by these abuttingsurfaces is in conjunction with the TEM accommodating part 53, and as aresult, the gap is a path in which the TEM accommodating part 53 inconjunction with the very low temperature freezing space is inconjunction with a general freezing space. Therefore, the gap betweenthe grill fan 51 and the abutting surface of the shroud may be a paththrough which the cool air in the very low temperature freezing spaceleaks into the general freezing space.

Accordingly, in the present invention, a first sealant 61 is pressed andinterposed between the rear surface of the grill fan 51 of the peripheryof the TEM accommodating part 53 and the abutting surface 561 of theshroud overlapping the rear surface. Ethylene propylene diene monomer(EPDM) rubber having excellent sealing performance may be applied as thesealant. A material of the sealant may be applied to second to fourthsealants, which will be described below, as well as the first sealant.

Meanwhile, since a temperature difference of about 30° C. is generatedbetween the very low temperature freezing space and the general freezingspace, a sealing force should be sufficiently secured and a sufficientoverlapping width is required even when a sealant is interposedtherebetween. On the other hand, in order to maintain such anoverlapping width, an overlapping region of the grill fan and theabutting surface of the shroud should be secured as a predeterminedwidth or more, and the overlapping region is a factor which occupies avolume of the freezer compartment or the very low temperature freezercompartment.

In consideration of this fact, in the present invention, the rear rib511 extending rearward from the rear surface of the grill fan 51 isformed. The rear rib 511 is provided in an outer periphery of the rearsurface of the grill fan 51 to be slightly spaced apart from the TEMaccommodating part 53. More particularly, the rear rib 511 is formed ata side farther outward from the TEM accommodating part 53 than theposition at which the rear surface of the grill fan and the abuttingsurface 561 of the shroud overlap.

In addition, similarly, the rib abutting surface 562 extending rearwardto be in contact with the inner surface of the rear rib 511 is providedon the outer circumferential surface of the abutting surface 561 of theshroud. That is, the abutting surface 561 and the rib abutting surface562 are bent to form a stepped shape. Therefore, the abutting surface561 of the shroud and the rib abutting surface 562 are brought intocontact with the rear surface of the grill fan 51 and the rear rib 511in an L shape. Also, a second sealant 62 is interposed and pressedbetween the rear rib 511 and the rib abutting surface 562.

In this manner, when the first sealant and the second sealant arerespectively interposed between two abutting portions of the bent shape,a sealing force may be more reliably secured. The first sealant and thesecond sealant may be separately manufactured and interposed asillustrated. Further, the first sealant and the second sealant may beintegrally manufactured to have an L-shaped cross section, and may beinterposed and pressed between the bent abutting surfaces.

In the rear rib 511 and the rib abutting surface 562, a sealing forcemay be secured even in a narrow space, and the assembly of the TEMassembly 100 fixed to the rear surface of the abutting surface 561 ofthe shroud due to a characteristic of the stepped shape may be furtherfacilitated. That is, when the outer edge of the flange 112 provided inthe module housing 110 of the TEM assembly 100 is manufactured to bemerged to some extent, that is, slightly, with the inside of the ribabutting surface 562, the outer circumferential surface of the flange112 of the TEM assembly 100 is loosely fitted into the stepped shape bythe rib abutting surface 562 when the TEM assembly 100 is fixed to thegrill fan assembly 50, and thus the TEM assembly 100 may be easily fixedto the grill fan assembly 50 while a position of the TEM assembly 100 isaccurately regulated.

That is, the stepped structure has an advantage of providing ease ofassembly of the TEM assembly 100 as well as ensuring the sealing forceof the gap between the grill fan and the shroud.

Further, a gap may also be generated in the overlapping region in whichthe abutting surface 561 of the shroud and the flange 112 of the modulehousing 110 are in contact with each other, and cool air in the very lowtemperature freezing space may be discharged into the general freezingspace through the gap. In consideration of this fact, in the presentinvention, a third sealant 63 is disposed in the overlapping region inwhich the abutting surface 561 of the shroud and the flange 112 of themodule housing 110 overlap. In this case, in order to secure a sealingforce, a width of the third sealant 63 should be sufficiently secured.

However, according to the present invention, since the spacer 111extending rearward from the flange 112 of the module housing 110 isprovided and a rear end of the spacer 111 is supported by the inner case12 located behind the grill fan assembly 50, an adhesion force betweenthe rear surface of the abutting surface 561 and a front surface of theflange 112 may be further secured due to the spacer 111.

In the present invention, a width w of the third sealant 63 ranges from5 mm to 15 mm. When the width of the third sealant 63 is less than 5 mm,there is a problem in that the sealing force is significantly reduced.In the present invention, the sealing force may be secured even when thewidth of the sealant is only about 5 mm, which is a result of asupporting force of the above-described spacer being added thereto. Whenthe width of the third sealant is more than 15 mm, there is littleimprovement in the sealing force for preventing leakage of cool air andonly a dimension is unnecessarily increased.

According to the above-described structure, sealing of each of thecomponents provided for fixing the TEM assembly 100 to the grill fanassembly 50 and a shape portion thereof may be secured, and the assemblyof the TEM assembly 100 to the grill fan assembly 50 may be facilitated.

For reference purposes, the accommodating groove 113 is provided toextend rearward relative to the flange 112. The flange 112 is fixed tothe grill fan 51 defining a rear surface of the freezer compartment withthe shroud 56 interposed therebetween. However, as described above, thethermoelectric element and the heat sink of the TEM assembly arepreferably disposed in a separate space from the freezer compartment.

Accordingly, in the present invention, the accommodating groove 113 isformed to extend rearward relative to the flange 112, configurations ofthe assembly are accommodated in the accommodating groove 113 in theorder of the heat sink, the thermoelectric element, and the cold sink,and thus the heat sink and the thermoelectric element are located behindthe space defined as the freezer compartment.

The above-described structure may also be applied to the installationstructure of the TEM assembly 100, as illustrated in FIG. 21. Since theinner space of the TEM accommodating part 53 should be isolated from thestorage space of the refrigerator compartment 30, a sealant may beinterposed between the rear surface of the flange 112 of the modulehousing 110 and the front surface of the inner case 12.

Similarly, a sealant may also be interposed between a portion in whichthe rear surface of the TEM accommodating part 53 of FIG. 21 is incontact with the inner case 12, and more particularly, the front surfaceof the flange 112 of the module housing 110 in close contact with theinner case 12, and the inner case 12.

A width of the sealant may also range from 5 to 15 mm like theabove-described width w.

[Sealing Structure of Very Low Temperature Freezer Compartment]

Hereinafter, a gap which is generated in the assembled structure of thevery low temperature freezer compartment of the present invention andthe sealing structure between the very low temperature case and the verylow temperature compartment door will be described with reference toFIGS. 23 to 26.

As described above, the TEM accommodating part 53 protruding forward isprovided in the grill fan 51, and the very low temperature case 210,which defines an overall exterior of the very low temperature freezercompartment 200, is coupled to the TEM accommodating part 53. The guiderails 212, which guide a sliding movement forward and backward viaauxiliary rails 15-1 provided on the side surface of the inner case 12and the side surface of the partition wall 42, are provided on both sidesurfaces of the very low temperature case 210. The opening 211, which isopen to accommodate the TEM accommodating part 53, is provided on therear surface of the very low temperature case 210. Therefore, when thevery low temperature case 210 is pushed rearward from the front of thefreezer compartment 40 while the guide rails 212 are coupled to eachother to be guided by the rails or the auxiliary rail, the TEMaccommodating part 53 is fitted into the opening 211 such that the innercircumferential surface 211 a of the opening 211 and the outercircumferential surface 534 of the TEM accommodating part 53 face eachother.

The inner circumferential surface 211 a has a predetermined depth andoverlaps the outer circumferential surface 534 of the TEM accommodatingpart 53 to surround the TEM accommodating part 53. The innercircumferential surface 211 a and the outer circumferential surface 534have a predetermined pressure and are in close contact with each other.

According to the present invention, a fourth sealant 64 is interposedand pressed between the inner circumferential surface 211 a and theouter circumferential surface 534. When the fourth sealant 64 isinterposed and pressed between the inner circumferential surface 211 aand the outer circumferential surface 534 such that the innercircumferential surface 211 a and the outer circumferential surface 534are coupled to each other, the very low temperature case 210 is fixed tothe TEM accommodating part 53 by the inner circumferential surface 211 aand the outer circumferential surface 534 being fastened to each other.Therefore, according to the present invention, when the fourth sealant64 is interposed between the inner circumferential surface 211 a and theouter circumferential surface 534 and the very low temperature case 210is pushed rearward, the very low temperature case and the TEMaccommodating part are firmly fixed to each other, and leakage of coolair in the very low temperature freezing space toward the freezercompartment through the gap between the very low temperature case andthe TEM accommodating part may be prevented.

As described above, although the inner circumferential surface 211 a hasa slight inclination relative to the outer circumferential surface 534,unlike the above-described other sealing portion, a sealing directionand an assembly direction of the overlapping region of the innercircumferential surface 211 a and the outer circumferential surface 534are substantially orthogonal to each other. Therefore, a compressionforce between the inner circumferential surface 211 a and the outercircumferential surface 534 may be less than a compression force betweenthe rear surface of the grill fan and the abutting surface 561 of theshroud and a compression force between the rear surface of the abuttingsurface and the flange 112 of the TEM assembly 100 as described above.

In consideration of this fact, in the present invention, a length OL ofthe fourth sealant disposed in the overlapping region of the innercircumferential surface 211 a and the outer circumferential surface 534may range from 30 mm to 40 mm. When an overlapping length (the length ofthe fourth sealant) is less than 30 mm, a sealing force is insufficient,and thus cool air in the very low temperature freezing space may bedischarged into the freezer compartment. When the overlapping length is30 mm or more, the sealing force for preventing the discharge of thecool air may be sufficiently secured, and when the overlapping length ismore than 40 mm, the sealing force is sufficiently secured but theoverlapping length is unnecessarily increased. When the overlappinglength is increased, the very low temperature freezing space is occupiedby the increased overlapping length, and thus a volume capacity thereofis reduced.

The structure in which the TEM accommodating part protrudes forward fromthe grill fan has an effect of securing an overlapping range for thevery low temperature case as described above, and has an effect ofpreventing loss of the cool air by allowing the cold sink of the TEMassembly accommodated in the TEM accommodating part to be disposed closeto the very low temperature freezing space.

In addition, according to the present invention, a rear surface of aperiphery of the opening of the very low temperature case 210 may be incontact with a front surface of the periphery of the TEM accommodatingpart of the grill fan. Accordingly, there is an effect in that a sealingforce is improved via the L-shaped sealing structure being disposedbetween the grill fan and the shroud described above. Similarly, as thecase in which the sealant is interposed between the innercircumferential surface 211 a and the outer circumferential surface 534,the sealant may be interposed and pressed between the rear surface 211-1of the periphery of the opening and a front surface of the grill fan.

Further, as described above, the inner circumferential surface 211 aincludes a surface inclined outwardly in the rearward direction, theouter circumferential surface 534 also includes a surface inclinedoutwardly in the rearward direction in a shape corresponding to theinner circumferential surface, and thus assembly of the very lowtemperature case to the TEM accommodating part may be smoothlyperformed. Such a tapered angle may range from about 1 to 5°.

The above-described structure may be applied to an installationstructure of the very low temperature freezer compartment 200illustrated in FIG. 21. That is, the sealant may be pressed andinterposed even in a portion in which the rear surface of the very lowtemperature case 210 is in contact with the inner case 12, and thesealant may be pressed and interposed between the inner circumferentialsurface of the opening of the very low temperature case 210 and theouter circumferential surface of the TEM accommodating part 53.

In other words, the very low temperature freezer compartment and therear wall may be reliably sealed through a structure in which the rearwall of the storage space cooled by the refrigeration cycle coolingsystem is in contact with the rear surface of the very low temperaturefreezer compartment and the sealant is pressed and interposedtherebetween, and/or a structure in which the outer circumferentialsurface of the TEM accommodating part provided on the rear wall is incontact with the inner circumferential surface of the opening providedin the rear surface of the very low temperature freezer compartment andthe sealant is pressed and interposed therebetween.

The space between the outer case 213 of the very low temperature case210, which defines a rear surface and upper, lower, left, and rightsurfaces of the very low temperature freezing space, and the inner case214 is filled with the heat insulating material 80 as described above,and thus an exchange of heat between the very low temperature freezingspace and the freezer compartment may be prevented.

Meanwhile, an inside of the very low temperature compartment door 220which shields the open front of the very low temperature case 210 isalso filled with the heat insulating material 80 such as the foam heatinsulating material 81, and thus an exchange of heat between the verylow temperature freezing space and the freezer compartment may beprevented. However, since the very low temperature compartment door 220is configured to open and close the front of the very low temperaturecase, a gap may be generated between the very low temperaturecompartment door 220 and a front end of the very low temperature case210, and heat may be introduced into the very low temperature case orcool air inside the very low temperature case may be discharged into thefreezer compartment through the gap.

In consideration of this fact, in the present invention, a gasket 65made of silicone is installed on an outer edge of a rear surface of thevery low temperature compartment door 220 to be in close contact with afront surface of the very low temperature case. However, unlike a gasketinstalled in a conventional refrigerator door, since the above-describedgasket 65 is a −50° C. environment inside the very low temperaturefreezing space and a −20° C. environment outside the very lowtemperature freezing space, an elastic force of the gasket may belowered and the cool air in the very low temperature freezing space maybe leaked.

In consideration of this fact, in the present invention, a compressionstructure is further provided to further provide a compression force forpushing the very low temperature compartment door 220 toward the verylow temperature case 210.

Briefly, the compression structure may be the freezer compartment door22. That is, in a state in which the freezer compartment door 22 isclosed, a structure such as the door basket 27 installed inside thefreezer compartment door 22 pushes the very low temperature compartmentdoor 220 rearward, and thus the very low temperature compartment door220 may be pressed toward the very low temperature case 210.

Further, the compression structure may include a magnetic substance 230such as a magnet embedded in a portion at which the very low temperaturecase 210 and the very low temperature compartment door 220 face eachother. Referring to FIG. 8, the front end of the very low temperaturecase 210 is in the form of a rectangular frame, and the outer edge ofthe rear surface of the very low temperature compartment door 220 facesthe front end of the very low temperature case. Therefore, asillustrated in FIG. 24, when the magnetic substance 230 is embedded inall or a portion of the front end of the very low temperature case 210along an edge thereof and the magnetic substance 230 is embedded in thevery low temperature compartment door 220 at a position corresponding toa position at which the magnetic substance of the very low temperaturecase is embedded, the very low temperature compartment door 220 ispressed against the very low temperature case 210 by attraction betweenthe two magnetic substances.

The compression structure may be a structure in which a protrusion 240and a locking groove 245 respectively provided in the very lowtemperature case 210 and the very low temperature compartment door 220are engaged. Referring to FIGS. 24 and 26 which is a cross-sectionalview of the very low temperature case and the very low temperaturecompartment door without the very low temperature tray when viewed fromthe front, outwardly protruding protrusions 240 are provided on bothsides of the very low temperature compartment door 220, and lockinggrooves 245 into which the protrusions are fitted may be formed insideprotrusions 219 protruding forward from the very low temperature case210. Therefore, when the very low temperature compartment door 220 ispushed and closed, the locking groove 245 and the protrusion 240 may bemaintained in an engaged state so that the compression force for pushingthe very low temperature compartment door 220 toward the very lowtemperature case 210 may be maintained.

In the embodiment of the present invention, a structure in which theprotrusions 240 are provided on the very low temperature compartmentdoor 220 and the locking grooves 245 are installed at the very lowtemperature case 210. However, the locking groove 245 may be provided inthe very low temperature compartment door 220 and the protrusions 240may be provided in the very low temperature case 210. In addition, thestructure of the locking groove and the protrusion is not limited to theillustrated form, the protrusions may be deformed in various forms suchas a saw or a hook, and the locking groove may have a shape in which theprotrusion may be locked in correspondence with the shape of theprotrusion.

A pushing structure of the door basket of the freezer compartment door,a structure of the magnetic substance, and a structure of theabove-described protrusions and locking grooves may be appliedindividually or in combination to the refrigerator. A structure of adamping closure 216, which will be described below, may also be appliedthereto.

Referring to FIG. 24, an outer rail guide 221 is installed below thevery low temperature compartment door 220 to extend rearward. Inaddition, the rail guide 221 is mounted below the very low temperaturecase 210, and an outer rail 215 is installed to allow the rail guide toslide back and forth. The rail guide 221 and the outer rail 215 may bedisposed outside the very low temperature freezing space, that is, inthe space of the freezer compartment, and may be provided with a metalmaterial having high rigidity.

Since the very low temperature freezing space is an extremely lowtemperature environment of −50° C., when the rail and the rail guide,which are made of a metal material having good thermal conductivity, aredisposed in the very low temperature freezing space of the very lowtemperature case 210, moisture which is absorbed from food while coolair is circulated may stick to the rail and the rail guide of the metalmaterial unlike the very low temperature compartment door 220 and thevery low temperature tray 226, which are made of a synthetic resinmaterial. This directly affects an opening and closing operation of thevery low temperature compartment door. Also, it is difficult to defrostwater adhered to the rail and the rail guide of the metal material.

However, when the rail and the rail guide are made of a synthetic resinmaterial, the synthetic resin material may be deformed into a fragilestate in the extremely low temperature environment, and thus the railand the rail guide may be damaged when subjected to an external forceand friction.

As described above, in the present invention, the rail is not disposedin the very low temperature freezing space, the outer rail 215 of themetal material is installed on a bottom portion of the very lowtemperature case as described above, and the outer rail guide 221 isinstalled below the rear surface of the very low temperature compartmentdoor 220. Therefore, the outer rail 215 and the outer rail guide 221support a loading and unloading operation of the very low temperaturetray 226. Meanwhile, when the rail is disposed outside the very lowtemperature freezing space as described above, the very low temperaturefreezing space may be further secured.

However, in order to prevent sagging of the very low temperature tray bya self-weight of the very low temperature tray 226 and a self-weight offood contained in the very low temperature tray 226, an additional subrail and sub rail guide of a synthetic resin material may be furtherprovided on a side surface or a bottom surface of the very lowtemperature tray. In the embodiment of the present invention, in orderto prevent such sagging and to maintain a space between the very lowtemperature tray and the bottom of the very low temperature freezercompartment, a structure of ribs 214 b and 226 a described above withreference to FIG. 9 has been illustrated.

According to the present invention, the damping closure 216 provided onthe outer rail 215 or the outer rail guide 221 may be further providedas a pressing structure of the very low temperature compartment doorwith respect to the very low temperature case. In the embodiment of thepresent invention, a structure in which the damping closure 216 isinstalled behind the outer rail 215 is illustrated. For example, whenthe very low temperature compartment door 230 is closed to some extent,for example, about 80% of a total inlet stroke S (see FIG. 24), an endof the outer rail guide 221 reaches the damping closure 216, and theouter rail guide 221 is moved rearward by a contractive force of anelastic body 216-2 configured of a tension spring in the damping closurewhile being locked and fixed to a locking bracket 216-1 of the dampingclosure 216 even when a user does not exert an external force thereon. Aguide protrusion 216-11 of the locking bracket 216-1 is fitted into aguide slot 216-4 and is moved along the guide slot. In this case, sincethe elastic body may be subjected to a damping force by a viscous oil216-3 in the damping closure, the rail guide 221 may be slowly pulledrearward at a controlled speed, and the very low temperature compartmentdoor may be brought into close contact with the very low temperaturecase by an urging force of the elastic body. Since the viscous oil is inan atmosphere of the freezer compartment, it is preferable for oilhaving an appropriate viscosity at a temperature of the correspondingatmosphere to be used as the viscous oil.

Conversely, when the very low temperature compartment door 230 isopened, the very low temperature compartment door 230 should be pulledat about 20% of total outlet stroke at the beginning such that theurging force of the elastic body 216-2 is overcome and the elastic body216-2 shrinks. When pulling force is more than 20% of the total outletstroke, the outer rail guide 221 may be easily released and unloadedfrom the locking bracket 216-1 of the damping closure 216. When theouter rail guide 221 is released from the locking bracket of the dampingclosure 216, the locking bracket is positioned at a locking position216-41 of the guide slot 216-4 and stays at the corresponding position.

In addition to the damping closure 216 having the above-describedstructure, any closure may be applied to the present invention as longas it is installed on the outer rail or the outer rail guide and has astructure that can elastically urge the outer rail guide rearward.

According to the present invention, it should be apparent that it isalso easy to assemble various components for implementing the very lowtemperature freezer compartment while preventing leakage of cold air inthe very low temperature freezing space toward the freezer compartment.

In the embodiment of the present invention, a structure in which the TEMassembly 100 is disposed at the rear of the freezer compartment 40 andin the rear of the very low temperature freezer compartment 200 isillustrated. However, the TEM assembly 100 is not limited to such aposition. For example, the TEM assembly 100 may be embedded in an upperportion of the inner case 12 of the freezer compartment to be locatedabove the very low temperature freezer compartment 200. Since the heatsink 150 of the TEM assembly 100 allows the refrigerant of therefrigeration cycle cooling system 70 of the refrigerator to flow intothe heat sink to be cooled using heat conduction, there is no need to bein contact with air. Therefore, a structure in which the TEM assembly100 is embedded in the upper portion of the inner case 12 of the freezercompartment may also be applied to the present invention.

According to the present invention, an extremely low temperature can besmoothly implemented and maintained by all gaps around a very lowtemperature freezing space through which it is possible for a very lowtemperature freezing space to be in conjunction with a freezing space ofa general freezer compartment being thoroughly sealed.

According to the present invention, a refrigerator can have a structurein which a TEM assembly is easily assembled and also reliably sealed.

According to the present invention, assembly and sealing of a very lowtemperature case and a grill fan assembly is simply and reliablyperformed, and sealing of the very low temperature case and a very lowtemperature compartment door, which performs opening and closing, isreliably performed, and thus very low temperature freezing can beimplemented and maintained.

In addition to the effects described above, specific effects of thepresent invention have been described in the above detailed descriptionof the embodiments of the invention.

While the present invention has been described with reference to theillustrated drawings, the present invention is not limited to thedisclosed embodiments and the drawings. It should be clear to thoseskilled in the art that various modifications may be made within thescope of the invention. In addition, although operational effectsaccording to the configuration of the present invention have not beenexplicitly described while explaining the embodiments of the presentinvention, it should be appreciated that effects predictable through thecorresponding configuration can also obtained.

What is claimed is:
 1. A refrigerator comprising: a storage spaceconfigured to be cooled by a refrigeration cycle cooling system; a wallthat is located at a first side of the storage space and that defines aboundary of the storage space at the first side of the storage space; alow temperature case that is located in the storage space and that isarranged adjacent to a portion of a first surface of the wall, the firstsurface facing the storage space; a thermoelectric element module (TEM)assembly that is located at a first side of the low temperature case andthat is configured to supply cool air to the low temperature case; and aTEM accommodating part that protrudes from the first surface of the walland that accommodates the TEM assembly, wherein the low temperature caseincludes an inner circumferential surface that defines an opening thataccommodates the TEM accommodating part, the inner circumferentialsurface surrounding and facing an outer circumferential surface of theTEM accommodating, wherein both of the inner circumferential surface ofthe low temperature case and the outer circumferential surface of theTEM accommodating part are outwardly inclined and extend toward thewall, and wherein the refrigerator further comprises a sealant that isinterposed between the inner circumferential surface of the lowtemperature case and the outer circumferential surface of the TEMaccommodating part and that is pressed by the inner circumferentialsurface of the low temperature case and the outer circumferentialsurface of the TEM accommodating part, the sealant being configured toseal a gap between the inner circumferential surface of the lowtemperature case and the outer circumferential surface of the TEMaccommodating part and to couple the inner circumferential surface ofthe low temperature case and the outer circumferential surface of theTEM accommodating part.
 2. The refrigerator of claim 1, wherein aperipheral surface of the opening contacts a peripheral surface of theTEM accommodating part, and wherein a sealant is applied between theperipheral surface of the opening and the peripheral surface of the TEMaccommodating part to couple the peripheral surface of the opening tothe peripheral surface of the TEM accommodating part.
 3. Therefrigerator of claim 1, wherein a portion of the inner circumferentialsurface overlaps with the outer circumferential surface, and wherein alength of the portion of the inner circumferential surface is between 30and 40 mm.
 4. The refrigerator of claim 1, wherein each of the innercircumferential surface of the low temperature case and the outercircumferential surface of the TEM accommodating part defines a taperedangle in a range from 1 to 5° with respect to a horizontal plane.
 5. Therefrigerator of claim 1, further comprising: a low temperaturecompartment door that is configured to open or close an opening of thelow temperature case, the opening being located at a second side of thestorage space; and a gasket that is configured to shield a gap betweenthe low temperature compartment door and the low temperature case. 6.The refrigerator of claim 5, further comprising: a first magnetic unitthat is coupled to the low temperature compartment door; and a secondmagnetic unit that is coupled to the low temperature case, wherein thefirst magnetic unit and the second magnetic unit are configured toattract each other and compress the gasket.
 7. The refrigerator of claim5, further comprising: a protrusion that is coupled to the lowtemperature compartment door; and a locking groove that is coupled tothe low temperature case and that is configured to be engaged with theprotrusion, wherein the protrusion and the locking groove are engagedwith each other and configured to compress the gasket.
 8. Therefrigerator of claim 5, further comprising: a low temperature tray thatis coupled to the low temperature compartment door and that is movablebetween a first position and a second position, wherein, (i) in a statein which the low temperature tray is located at the first position, atleast one portion of the low temperature tray is outside of the lowtemperature case, and (ii) in a state in which the low temperature trayis located at the second position, the low temperature tray is insidethe low temperature case; an outer rail guide that is coupled to the lowtemperature tray through the low temperature compartment door and thatis configured to be moved with the low temperature tray; an outer railthat is coupled to the low temperature case and that is configured toguide the outer rail guide in moving the low temperature tray betweenthe first position and the second position; and a damping closure thatis coupled to the outer rail or the outer rail guide and that isconfigured to move the outer rail guide at a first speed.
 9. Therefrigerator of claim 5, further comprising: a refrigerator door that isconfigured to press the low temperature compartment door and compressthe gasket in a state in which the refrigerator door is closed.